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Sabremetrics 101

Hms_surprise_tiny by Graham on Comment 327 comments

Got questions about statistical analysis? Ask. We might be able to help.

There are people of all sorts on Lookout Landing. Some of you are new to this, some are old hands. Everyone should feel free to chime in with questions, answers, points of contention, etc. Just try to be nice.

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Links to any credible defense system would be helpful

As would instructions on how to calculate WAR

by JI on Dec 14, 2008 9:03 PM PST reply reply actions actions   0 recs

Ugh.

I need a website that does it for me.

by JI on Dec 14, 2008 9:15 PM PST to parent up reply reply actions actions   0 recs

It would be nice

I’m hoping fangraphs combines wRAA and UZR to make a WAR stat.

by chrisisasavage on Dec 14, 2008 9:21 PM PST to parent up reply reply actions actions   0 recs

.

wOBA*, <x< defensive number (i.e. I’d put 10 for Beltre because he’s a 5<x<15 defender,) positional adjustment and playing time expressed as a decimal. Tango has a brief explanation of how to figure playing time in his original calculation WAR post.

by acblue on Dec 14, 2008 9:41 PM PST to parent up reply reply actions actions   0 recs

Pujols

.458, 20, -1, .85 = 8.56

by JI on Dec 14, 2008 9:42 PM PST to parent up reply reply actions actions   0 recs

A-Rod, 2003

8.22

Hmmm, seems kind of low.

*Though I did have to use the NL sheet cos the AL one is fucked up at the moment.

by JI on Dec 14, 2008 9:51 PM PST to parent up reply reply actions actions   0 recs

I would use 2002

Because he was even better, but I don’t have wOBA* for 2002.

by JI on Dec 14, 2008 9:52 PM PST to parent up reply reply actions actions   0 recs

Yes it is.

If anyone knows how to carry rules through an entire column, that would be good to know.

by acblue on Dec 14, 2008 9:52 PM PST to parent up reply reply actions actions   0 recs

Silly kids

They don’t measure runs prevented on the scoreboard. Just give me a guy who hits RBI’s or hits for average, and puts his heart into it, and hustles on every play, and I’ll show you a good player. You guys valuing make believe stats like UZR and overvalue the rally-killing walk.

For pitchers give me ERA or W/L, and that’s all I need. Joe Morgan told me so.

by chrisisasavage on Dec 14, 2008 9:44 PM PST to parent up reply reply actions actions   0 recs

here's a pretty good start

http://www.fangraphs.com/blogs/index.php/wrc-and-wraa
take the wRAA, add defensive value, 22.5 runs for replacement level, Tango’s positional adjustments, divide by 10 and presto

by Bearskin Rugburn on Dec 14, 2008 9:52 PM PST to parent up reply reply actions actions   0 recs

Try

(wRAA * PA / 700 + 22.5 + UZR/162 (UZR/150 * 162/150) + Positional Adjustment) * PA / 700

by chrisisasavage on Dec 14, 2008 9:55 PM PST to parent up reply reply actions actions   0 recs

I meant

wRAA * 700 / PA for the first bit

by chrisisasavage on Dec 14, 2008 9:57 PM PST to parent up reply reply actions actions   0 recs

Here they are:

+12.5 C
+7.5 SS
+2.5 2B/3B/CF
-7.5 LF/RF
-12.5 1B
-22.5 DH

by Matthew on Dec 14, 2008 9:16 PM PST to parent up reply reply actions actions   0 recs

A lot of it has to do with talent pools.

This somewhat came up before here at LL (I think), but the notion of a defensive spectrum as Bill James laid it out is correct, but not the end-all, be-all. It’s simplistic and glosses over that positions require different skills and those skills are not linearly less important as you move down the spectrum.

In other words, a poor catcher cannot just be converted into an average SS.

Because of that, the distinctions between certain positions become muddy. We’ve seen more than a few people move between 2B and CF (Upton, Biggio, Burke), and 3B ends up as sort of an isolated position. Rarely staffed by fielders competent enough to hold down SS, but still needing a strong enough arm that 1B would be a waste.

by Matthew on Dec 14, 2008 9:22 PM PST to parent up reply reply actions actions   0 recs

My concern,

Thridbase is almost always out hits second on a league wide basis, and it generally requires less range to play.

by JI on Dec 14, 2008 9:30 PM PST to parent up reply reply actions actions   0 recs

You can get by at second base without a great first step or a great arm...

…but they are still awfully helpful towards increasing your range, or turning double plays. They also see 60 fewer BIZ each year, so any shortcomings are exposed somewhat less often than shortcomings at 2B are.

My intuition tells me that if third basemen outhit second basemen as a group, then the pool of players who can defensively handle third base is larger than the pool of players who can defensively handle 2B. Thus, 2B are a more scarce resource so that an average overall 2B should be more valuable than an average 3B.

Like I said, that’s my intuition, so I’m certainly open to arguments to the contrary. I’m still not 100% convinced by anyone’s argument what the “correct” way to do positional adjustments are.

(Further caveat: If the claim is that the 3B adjustment is +2.5 and the RF/LF adjustment is -7.5, then at most I’m thinking that 3B should move down to +0 or -2.5, and that’s a pretty small difference from +2.5, all things considered.)

by ubelmann on Dec 14, 2008 11:22 PM PST to parent up reply reply actions actions   0 recs

I'm not stating my beliefs here, really

I’m just providing a possible argument as to the why

by Graham on Dec 14, 2008 11:31 PM PST to parent up reply reply actions actions   0 recs

Cool

I definitely agree that that’s a possible argument and that it’s good to keep in mind that the different positions require somewhat different skills.

by ubelmann on Dec 14, 2008 11:37 PM PST to parent up reply reply actions actions   0 recs

I think I heard somewhere

that 3B hitting historically is about as good as 2B hitting. I don’t know where I heard that. Tango maybe?

by Edgar for Pres on Dec 15, 2008 10:47 AM PST to parent up reply reply actions actions   0 recs

Put another way

There is no position where the skills necessary to excel there will also necessarily make you an excellent 3B.

Like Catcher, 3B relies on a unique combination of skills. However, those skills are not as rare in combination with good hitting as Catcher skills are, so 3B gets a smaller adjustment.

I like using semi-colons; they make me feel smart.

by Llewdor on Dec 15, 2008 12:05 AM PST to parent up reply reply actions actions   0 recs

Are these determined through regression analysis?

I understand the concept of why they would be weighted differently, I’m asking how these numbers are arrived at.

Formerly dpseadvr.

by Kermit. on Dec 14, 2008 9:21 PM PST to parent up reply reply actions actions   0 recs

To quote from Sean Smith, because he says it succintly

“These are based on defensive statistics, not offense. He looks at how players who play multiple positions perform when switching for one to another, with some consideration for handedness, as lefties do not play second, third, or short.”

by Matthew on Dec 14, 2008 9:22 PM PST to parent up reply reply actions actions   0 recs

I guess I'm not totally sold on using players switching positions to determine the positional adjustment

Even other than the SSS issue, I wouldn’t use, for instance, C→2B conversions to determine the relative adjustment between positions, even though that conversion happens every now and again, because the skills for the two positions are so different.

With other positions—like 2B and 3B—there are a lot more people who play both positions, and it might be tempting to use those players to figure out the adjustment, but there are still different skills required in playing the two positions. And it seems to me that players who play both positions aren’t necessarily a representative sample of defenders at each position, but that might be wrong.

by ubelmann on Dec 14, 2008 11:29 PM PST to parent up reply reply actions actions   0 recs

Dont have that offhand, but this raises an important point.

Namely, what’s the goal? Why should projecting RA next year be a worthwhile endeavor?

by Matthew on Dec 14, 2008 10:32 PM PST to parent up reply reply actions actions   0 recs

When it comes to pitching stats...

…I always think that it’s bizarre that projection systems have traditionally been measured with correlation to ERA, when we know that ERA is so team/luck-dependent.

If tRA describes to us what the pitchers do separately from what the defense does, and we want to know how good a pitcher is going to do in year N+1 (because we’re major league GMs and need to assemble a team for next year), it seems like we should be trying to project tRA, not RA or ERA. (Also, on general grounds I object to the use of correlation coefficient over something like a chi-squared statistic since the pitchers have different innings pitched totals, so the variance in each ERA or tRA is different, but that complaint probably belongs in a different discussion.)

by ubelmann on Dec 14, 2008 11:35 PM PST to parent up reply reply actions actions   0 recs

You need to check how good a stat is somehow

Just making up a stat and saying its good isn’t enough. Eventually you need to try to prove that its better than other stats already out there. You can’t just say “It should be good”. People want to know how good it actually is.

I’m not saying that tRA should be a great predictor of year N+1 but it should be better than FIP, xFIP, etc. If it isn’t then all that extra work Graham has done which should make it a better stat has in effect shown very little reward. Nobody wants to hear that and I think tRA is a better stat than anything out there right now but to validate that belief, we need to test it.

by Edgar for Pres on Dec 15, 2008 10:51 AM PST to parent up reply reply actions actions   0 recs

Yes, but you have to test it the right way and against RA is the wrong way.

The correlation between FIP/tRA and RA really is meaningless. It’s like proving wOBA is good by showing that it predicts RBI totals better in year N+1 than RBI in year N does. It doesn’t make sense.

The measure is how tRA (or better tRA*) correlates with tRA(*) N+1 compared against RA and RA N+1.

by Matthew on Dec 15, 2008 11:28 AM PST to parent up reply reply actions actions   0 recs

But how do you know that tRA is measuring anything that relates to runs allowed

To use your example, RBI totals in year N predict RBI totals in year N+1 well but that doesn’t mean that RBI is a valuable stat.

How can you prove to me that the weights used to calculate tRA in the end produce a stat that effectively measures the talent of a pitcher?

I’m a huge fan of tRA but I do think it needs to be related back to something rooted in reality to prove its worth.

by Edgar for Pres on Dec 15, 2008 11:55 AM PST to parent up reply reply actions actions   0 recs

Yes it is

Which team wins more games? The team with the higher RA or tRA. RA is an outcome stat. In the end of the day all of our stats are trying to be as good as a stat that keeps track of outcomes.

by Edgar for Pres on Dec 15, 2008 12:02 PM PST to parent up reply reply actions actions   0 recs

Ok here's a question

How do you prove that FIP is a useful stat? I understand that K, BB, and HR are useful stats but how do you prove to me that the combination of the three and the weights assigned are valid and the final numbers FIP produces have actual meaning?

by Edgar for Pres on Dec 15, 2008 12:06 PM PST to parent up reply reply actions actions   0 recs

You show that HR, K and BB are independent of the defense and that their repeatability yeat-to-year

is much higher than superfluous things like hits allowed. You then do modeling based on linear weighting to determine how the outcomes relate to each other in value.

by Matthew on Dec 15, 2008 12:09 PM PST to parent up reply reply actions actions   0 recs

Can you tell someone how "good" FIP is?

Can you tell me if xFIP is better than FIP? Can you tell me how much better xFIP is than FIP?

by Edgar for Pres on Dec 15, 2008 12:10 PM PST to parent up reply reply actions actions   0 recs

'the weights assigned are valid'

The weights assigned must be valid as the process of deriving the weights is giving a true comparison of the HR/BB/K outcomes and runs scored.

It’s a by definition thing, as I’ve said many times

by Graham on Dec 15, 2008 12:21 PM PST to parent up reply reply actions actions   0 recs

I'm happy you are confident in them

I am too. I just like the idea of testing this type of stuff when you get to the final result. Since I guess this is impossible then I guess I’ll just have to be fine with that.

by Edgar for Pres on Dec 15, 2008 1:06 PM PST to parent up reply reply actions actions   0 recs

I also want to make it clear

I know tRA doesn’t predict RA because it removes defense from the equation. I just want a method to demonstrate that the stat actually relates back to runs allowed.

How do I know that a pitcher with a 3.2 tRA is better than a pitcher with a 3.5 tRA? Do you have anything that will back that up?

by Edgar for Pres on Dec 15, 2008 12:09 PM PST to parent up reply reply actions actions   0 recs

On a league-wide scale

tRA has an “error” rate of less than 1% on actual runs allowed.

by Matthew on Dec 15, 2008 12:10 PM PST to parent up reply reply actions actions   0 recs

Do you have this same problem with wOBA?

It’s derived from the average outcomes of a play. The more good outcomes that a player produces, the better.

by Graham on Dec 15, 2008 12:13 PM PST to parent up reply reply actions actions   0 recs

I don't have a "problem" with wOBA or tRA

I’m just wondering if there is a good way we can test these stats to make them more accurate.

by Edgar for Pres on Dec 15, 2008 12:16 PM PST to parent up reply reply actions actions   0 recs

Their accuracy comes from properly weighting the stats to begin with

If they are properly weighted, they are, by definition, accurate.

by Graham on Dec 15, 2008 12:17 PM PST to parent up reply reply actions actions   0 recs

SLG, for example, is an improperly weighted stat

It’s 1/2/3/4 weightings don’t correspond to actual runs scored.

by Graham on Dec 15, 2008 12:19 PM PST to parent up reply reply actions actions   0 recs

Why would you want to do that when you know how misleading that can be?

I mean, Washburn had a 3.2 ERA in 05, and if you made a predictoin based on his 04 numbers, you’d have to come to the conclusoin that it’s crap.

by Bearskin Rugburn on Dec 15, 2008 12:13 PM PST to parent up reply reply actions actions   0 recs

I believe the whole thing about tRA

I buy everything you put into it. I just think there has to be a good way to take it all and compare it back to outcomes.

by Edgar for Pres on Dec 15, 2008 12:12 PM PST to parent up reply reply actions actions   0 recs

Exactly

It just looks at the pitching outcomes before the fielding process can scramble them

by Graham on Dec 15, 2008 12:16 PM PST to parent up reply reply actions actions   0 recs

Yeah got it

On a side note, do you have concerns about the stat being based on FB/LD/GB where these are slightly arbitrary? If you had hit locations and hit speed how much do you think this would improve the stat.

by Edgar for Pres on Dec 15, 2008 1:08 PM PST to parent up reply reply actions actions   0 recs

10% or so would be my off the cuff guess.

It does suck to rely on somebody’s FB/LD/GB distinctions instead of having a good BIP system, but since that’s only a part of the overall stat and a majority of them wouldn’t change with increased precision, I think the overall improvement would be significant, but relatively minor

by Matthew on Dec 15, 2008 1:11 PM PST to parent up reply reply actions actions   0 recs

I guess outcomes was the wrong word

I was thinking runs allowed but since the comparison between a talent stat and something like runs allowed can never be done totally unambiguously, then its a mute point.

I’m just built to think of problems from the standpoint of the scientific method and like to have many ways to test to see if my hypothesis was correct. I trust all the work you guys have done and love using tRA. If I write a paper and only have one way to back up my theory it probably won’t get published anywhere. If you can’t do anything else then that’s fine and that happens but it would be great to have a library of reasons why tRA is the shit.

by Edgar for Pres on Dec 15, 2008 1:16 PM PST to parent up reply reply actions actions   0 recs

The same way that you know that OBP is measuring something that relates to runs scored

Combine OBP with the other offensive stats to see how well it predicts runs scored within that season.

With tRA, combine it with other run prevention stats (specifically, those related to defense) and see how well it predicts runs allowed within that season.

Projecting RA in year N+1 is dependent upon how will you can: a) predict the future, b) measure a pitcher’s value, and b) measure a defense’s value.

by ubelmann on Dec 15, 2008 12:01 PM PST to parent up reply reply actions actions   0 recs

It measures the pitcher's role in runs allowed,

but because you can’t uncouple position players’ role in that from the number, it makes no sense to compare against it directly. If you must compare it to actual RA you would have to normalize RA to the defense behind the pitcher using whatever metrics are available and regress it against bad/good luck and park factors. But then you’re just calculating tRA from the other end.

by Bearskin Rugburn on Dec 15, 2008 12:05 PM PST to parent up reply reply actions actions   0 recs

I think one of the core issues here

is are you trying to predict RA with your stat or are you trying to measure a pitcher’s quality/value. If it’s the former, well, it’s a questionable goal. If it’s the latter, correlation with RA or FIP doesn’t matter. However, a good measure of a pitcher’s skill should be fairly predictive of itself, because outside of the natural variation a pitcher remains who he is.

by Bearskin Rugburn on Dec 15, 2008 12:01 PM PST to parent up reply reply actions actions   0 recs

I've only checked this for one year of tRA* back when I first came up with it

Correlation for park-unfactored tRA* to RA was over 0.70.

Need to do a longer study at some point, but that’s a really nice number.

by Graham on Dec 14, 2008 10:33 PM PST to parent up reply reply actions actions   0 recs

It's based on peripherals

that have better year to year correlation. FIP is pretty good, but HR is a problem, and not all batted balls are the same.

by chrisisasavage on Dec 14, 2008 9:17 PM PST to parent up reply reply actions actions   0 recs

I get that they are good

but how good are FIP, xFIP, tRA, and tRA*. I’d really like some numbers to evaluate the difference in accuracy between them all.

by Edgar for Pres on Dec 14, 2008 10:31 PM PST to parent up reply reply actions actions   0 recs

Since hit/fx is a impossible dream

what is the likelihood that we come up with the perfect hitting statistic?

by Robert on Dec 14, 2008 9:17 PM PST reply reply actions actions   0 recs

wOBA is not bad

Any linear weights type system is good for measuring hitting. The closest thing to perfect would be a regressed wOBA, which I believe wOBA* does. Park factors help too.

by chrisisasavage on Dec 14, 2008 9:20 PM PST to parent up reply reply actions actions   0 recs

Which makes sense

because as unreal as Pujols is a 0.468 wOBA cannot be a regressed statistic, except maybe for 2001-2004 era “Super-Bonds”

by chrisisasavage on Dec 14, 2008 9:24 PM PST to parent up reply reply actions actions   0 recs

You'll live.

I’d like to see if I could come up with a prOPS/wOBA hybrid that weights past run values on batted ball type with league average values, which should probably be better than straight up wOBA. But good god that’ll be complex.

by Graham on Dec 14, 2008 9:24 PM PST to parent up reply reply actions actions   0 recs

It would just be easier if they'd

come up with hit f/x or if there was something like Hit tracker for all batted balls.

by chrisisasavage on Dec 14, 2008 9:27 PM PST to parent up reply reply actions actions   0 recs

Even then it'd be difficult

A weakass grounder to shortstop from Bengie Molina is not the same as from Ichiro, so you’d have to look at past run values for the batter too

by Graham on Dec 14, 2008 9:28 PM PST to parent up reply reply actions actions   0 recs

I suspect

speed scores and handedness would be decent inputs for a regression.

I also suspect you’d still need to regress it against actual performance.

Of course I have no way of knowing that for sure.

by chrisisasavage on Dec 14, 2008 9:30 PM PST to parent up reply reply actions actions   0 recs

What is the age that pitchers and hitters are generally supposed to start declining at?

And do projection systems project declines and improvements on a case-by-case basis or just one general set of ages for everyone?

by Fogel on Dec 14, 2008 9:30 PM PST reply reply actions actions   0 recs

Depends on the system. PECOTA, being advanced, is more case-by-case

Hitters peak around 27 on average and therefore start declining at that age. However, 30 is a good mark for when hitters’ aging should start to be a concern. And that’s going to differ a lot based on the hitter’s skillset. See the USSM post about old-player skills for more.

Pitchers are a different beast entirely. Generally, pitchers velocity (and hitter’s defense) start declining as soon as the player’s body is done maturing, around his or her early 20s. But since pitching skills are so different, there’s isn’t yet a real good sense of aging curves for pitchers as a whole. Since they are the ones in command of the situation, they can take leaps forward (or back) with much greater frequency and effectiveness regardless of age.

by Matthew on Dec 14, 2008 9:38 PM PST to parent up reply reply actions actions   0 recs

It's my understanding that the projection systems (besides Marcel) look for similar players and aging curves to base projections on

which is why Ichiro is always such a problem. When they’re looking for similar players historically, does this mean looking for guys with similar traditional stat results (1B, 2B, 3B, HR, SB, etc.) or with similar peripherals (K%, K/BB, LD, etc.)?

by seattlebruin on Dec 14, 2008 9:41 PM PST to parent up reply reply actions actions   0 recs

Depends on the system

PECOTA uses more or less everything and weights them, I think.

by Graham on Dec 14, 2008 9:43 PM PST to parent up reply reply actions actions   0 recs

Marcel is never going to be better than a 'real' projection system

It is designed to be dumb, and the benchmark of a reasonable projection system is whether it can beat Marcel.

A comparison of the major systems. From BP and small sample, so take it with a grain or two of salt, but you should get the idea.

by Graham on Dec 14, 2008 9:46 PM PST to parent up reply reply actions actions   0 recs

Here is probably where I should register my correlation coefficient complaint

It seems silly to test projection systems for pitchers by doing a correlation coefficient against ERA—we could be perfectly projecting pitchers and have all of the variance buried in year-to-year defensive variation or most of the variation could be due to year-to-year pitching changes. But we don’t know by looking at ERA.

If FIP explains pitching performance best, then projection systems should try to project a pitcher’s FIP. If tRA explaisn pitching performance best, then projection systems should try to project a pitcher’s tRA. Etc.

Also, we miss a lot of pitchers by having to set a lower limit on IP. In 2008, there were 312 pitchers with 50+ IP. There were another 182 pitchers with 20+ IP, and we wouldn’t have to throw those out if we used something like a chi-squared statistic instead of correlation coefficient.

by ubelmann on Dec 14, 2008 11:52 PM PST to parent up reply reply actions actions   0 recs

It depends on what you're trying to project, right?

I mean, if you’re only interested in a player’s true talent level, then yeah, tRA* (or xFIP—pick your poison regarding which is actually getting the best defense independent measure) is probably the thing to look at.

But if you’re a GM trying to figure out what to do, then you need to account for your own park. GB% is really important for the Rockies and it’s not very important if he’s throwing in PetCo. Similarly, a GM knows exactly which defenders are on the field. The fly ball pitcher is more of a liability with a bad out field than a good one.

There’s no one-size fits all metric. tRA* seems great to me for a measure of pitching talent since it’s based on the run production associated, on average, with particular outcomes that are strictly out of the control of the defense and regressed by park factors and luck issues associated with unusual LD%, for example.

But if you want a projection metric for fantasy baseball, a metric designed to predict ERA is probably more your need.

by philosofool on Dec 15, 2008 8:31 AM PST to parent up reply reply actions actions   0 recs

Even if you were interested in fantasy baseball...

…it seems like you would project tRA and defense separately and then come up with an ERA projection.

by ubelmann on Dec 15, 2008 9:58 AM PST to parent up reply reply actions actions   0 recs

Depends on the skill/stat your talking about

Batting average peaks around 24, power hitting around 27, walks in the early 30s. Base stealing probably peaks for most players before they even arrive in the majors. And this all gets messy because there are stats and there are skills. Hitting for contact, pitch selection—those are skills, and they correlate with batting average, but the correlation isn’t perfect and measuring the skills is hard.

Pitching is even harder to understand. Some guys collapse as their velocity starts to drop off. Other guys adjust to the loss of velocity and remain good pitchers. Mussina, for example. Some pitchers learn control, others never do. Someone who knows more about pitching may be able to say more.

by philosofool on Dec 15, 2008 8:21 AM PST to parent up reply reply actions actions   0 recs

More of a sabermetrics history question than anything

but about when did VORP fall out of favor with analysts?

by BrianL on Dec 14, 2008 9:48 PM PST reply reply actions actions   0 recs

VORP for pitchers has always been bad

VORP for hitters is still a reasonable statistic to use, but over the last few years (I’d guess 2006 was when I first started hearing about this, but it may have been a point of discussion beforehand) it’s lost some lustre due to questions about the way they do replacement level and in favour of more accurate offensive stats.

by Graham on Dec 14, 2008 9:51 PM PST to parent up reply reply actions actions   0 recs

Yeah, I've always been under the impression VORP was a bad tool to use with pitchers.

I was curious mostly because I got into this scene in early 2007. In all that time I’ve only seen a few mentions of VORP in use with hitters, and I’m not sure if I’ve seen anyone at LL/USSM use it during that stretch.

by BrianL on Dec 14, 2008 9:57 PM PST to parent up reply reply actions actions   0 recs

Evan at BP a better stat was always Adjusted Runs Prevented (ARP).

But, for some reason they made a point of promoting VORP, and for the longest time they didn’t make ARP numbers available for starters. They wanted you to use Support-Neutral Winning Percentage or something instead. But that meant the only advanced stat they made available with which you could compare starters and relievers was VORP, so a lot of people relied on it.

I like using semi-colons; they make me feel smart.

by Llewdor on Dec 15, 2008 12:11 AM PST to parent up reply reply actions actions   0 recs

Yes, it's very outcomes based.

Pitchers’ VORP is heavily influenced by luck*.

  • Unexplained variance

I like using semi-colons; they make me feel smart.

by Llewdor on Dec 15, 2008 12:12 AM PST to parent up reply reply actions actions   0 recs

Damn SBN 2.0 for mangling my endnote

I like using semi-colons; they make me feel smart.

by Llewdor on Dec 15, 2008 12:12 AM PST to parent up reply reply actions actions   0 recs

I guess which begs the follow-up question

are guys who are really fast disproportionately likely to reach base via error on a groundball than players who are not fast?

by seattlebruin on Dec 14, 2008 9:54 PM PST to parent up reply reply actions actions   0 recs

We didn't choose to, that's Tango's formula.

And beside being a speed proxy, it’s rewarding people that reach base.

by Matthew on Dec 14, 2008 9:55 PM PST to parent up reply reply actions actions   0 recs

*shrug*

We haven’t put the time yet into investigating it. The key aspect to developing projection systems is finding what’s repeatable year-to-year. RBOE might correlate very well year to year as part of a player’s foot speed and GB tendencies. If so, it would be worthwhile to include it, or some facsimile of it.

by Matthew on Dec 14, 2008 10:08 PM PST to parent up reply reply actions actions   0 recs

I've asked this several times at USSM and Fangraphs

so at this point, if it’s a stupid question I’d rather just hear that so I can stop asking (although I’d then like to know why it’s stupid).

Is the 0 value in UZR a hypothetical constant (like replacement level hitting) or is it calculated as the average value of all players at a given position in that season (like Dewan’s +/-)

by Bearskin Rugburn on Dec 14, 2008 10:04 PM PST reply reply actions actions   0 recs

So if there were a hypothetical year

when several shortstops shifted to second, Utley had another incredible season and so on guys like Cano would be completely fucked for value. I guess this is where needing 3 years’ worth comes in.

by Bearskin Rugburn on Dec 14, 2008 10:14 PM PST to parent up reply reply actions actions   0 recs

Well, yes.

Because the group of people Cano would be competing against would have gotten better.

by Matthew on Dec 14, 2008 10:17 PM PST to parent up reply reply actions actions   0 recs

Past M's

Is there any way to find the defensive values of the 2001 M’s? I can’t find them anywhere

Or Ken Griffey Jr. value as a M? or the value of Buhner’s amazing sliding catches. haha.

by ghostsalmon on Dec 14, 2008 10:38 PM PST reply reply actions actions   0 recs

Yea

defensive efficiency. I think you can even find IF/OF splits using fangraphs, and I seem to remember someone going through this exercise but haven’t the initiative to go find it.

by Bearskin Rugburn on Dec 14, 2008 11:12 PM PST to parent up reply reply actions actions   0 recs

BP has park adjusted

Defensive Efficiency which is a little less rough

Don't believe the lies Bill!!!! look at the sparkly ERA!!! Sparkly, Sparkly!!! - McCovey Chronicles

by Trenchtown on Dec 14, 2008 11:31 PM PST to parent up reply reply actions actions   0 recs

Moneyball

I’m interested in sabremetrics, but not well versed. I read Moneyball, which describes Bean’s view on defense (i.e. that it doesn’t matter that much). On this site and on ussmariner, the authors talk often about how important defense is.

Question: Would Beane agree? Has he changed his view or did I just mis-read the book?

by solap1 on Dec 14, 2008 10:45 PM PST reply reply actions actions   0 recs

Beane

Just goes to show how great GMs will listen to others and even change their views. Not just have one stance and not change no matter what.

www.buhnerbuzzcuts.blogspot.com

by ghostsalmon on Dec 14, 2008 10:49 PM PST to parent up reply reply actions actions   0 recs

In addition

Defensive Metrics have come along way even since Moneyball, especially in what is publicly available. So Beane felt it was easier to find efficiencies in things that were easily quantified in value, once those undervalued things became properly valued it was time to move on to something else

Don't believe the lies Bill!!!! look at the sparkly ERA!!! Sparkly, Sparkly!!! - McCovey Chronicles

by Trenchtown on Dec 14, 2008 11:34 PM PST to parent up reply reply actions actions   0 recs

Beane has always been a "If it matters, measure it" kind of guy.

As a corollary to that, “If you can’t measure it, you can’t know to what extent it matters.”

In 2001, you couldn’t really measure defense. Beane knew enough to realise that the tools he had at his disposal were crap, so he ignored them. The functional result of this was to ignore defensive value completely, because he couldn’t measure it. He had no way to choose between two players based on defensive skills, so he made what is always the rational choice in the face of total uncertainty and deemed them equivalent. In all cases.

Rational decisions are often really counter-intuitive. When Moneyball came out I was only 3 years removed from finishing my academic work in Rational Decision Theory, so it all seemed really obvious to me, but I recognised that most people would disagree with me (and Billy).

I like using semi-colons; they make me feel smart.

by Llewdor on Dec 15, 2008 12:19 AM PST to parent up reply reply actions actions   0 recs

The functional result of this was to ignore defensive value completely, because he couldn’t measure it.

I think that’s overstating it.

by JI on Dec 15, 2008 12:28 AM PST to parent up reply reply actions actions   0 recs

Yeah

it mentioned in the book using a form of zone rating to measure Johnny Damon as the best defensive center fielder in the game but it didn’t make up for his particularly awful offensive year. The book glossed over the fact that was considerably below Damon’s talent level and improvement was almost insured

Don't believe the lies Bill!!!! look at the sparkly ERA!!! Sparkly, Sparkly!!! - McCovey Chronicles

by Trenchtown on Dec 15, 2008 12:32 PM PST to parent up reply reply actions actions   0 recs

Beane's all about targeting players that are undervalued

Flashy defence was overvalued at the time of Moneyball, which is why he wasn’t willing to pay for it. The market has shifted the other way for a while though.

by Graham on Dec 14, 2008 10:48 PM PST to parent up reply reply actions actions   0 recs

Do we have any evidence that this is actually true?

Or rather, that the “flashy” correlated with “defense” at all?

by marc w on Dec 15, 2008 12:26 AM PST to parent up reply reply actions actions   0 recs

I think it was that OBP was the great cheap resource

and he was going to use it.

When OBP became mainstream, he shifted his focus more towards run prevention.

by JI on Dec 14, 2008 10:48 PM PST to parent up reply reply actions actions   0 recs

Cust was still an above average OF making league minimum

His UZR/150 was -15… which is bad, but still 6 runs better than Ibanez was last year.

+25 for his bat, -15 for his glove, and -7.5 for position still leaves him 2.5 runs above average. Even if that A’s planned on playing him in LF for the whole season, it would still be a net positive, which is what matters in the end.

by MrIncognito on Dec 18, 2008 12:20 PM PST to parent up reply reply actions actions   0 recs

Another question sort of...

Does anyone have an examples of any fielder having a major shift in their defensive numbers in a good direction or bad direction?

www.buhnerbuzzcuts.blogspot.com

by ghostsalmon on Dec 14, 2008 10:47 PM PST reply reply actions actions   0 recs

Good direction, short term

Hanley Ramirez. But one year doesn’t mean all that much, and you almost never have a sea change over just one season unless a guy was playing through injury or something

bad direction, long term
everyone

by Bearskin Rugburn on Dec 14, 2008 11:16 PM PST to parent up reply reply actions actions   0 recs

Jason Bay

seems to have dropped off a cliff as a result of his knee issues. Was an average defender, now terrible. It’s hard to be completely sure because the sample with Pitt this season is small, he changed parks and the park he changed to is totally wonky (Green Monster). Still, he was enough plays below average that expecting him to go all the way back to average isn’t reasonable. (Besides, only about 1/4 of his games were in Boston.)

by philosofool on Dec 15, 2008 11:16 AM PST to parent up reply reply actions actions   0 recs

It's such an outlier that I would say it's reasonable he comes back up to average.

It’s a really small sample, there are extenuating circumstances and it’s way out of whack with his career numbers. That’s not to say it should be expected, but it’s certainly within the realm of possibility.

by acblue on Dec 15, 2008 11:39 AM PST to parent up reply reply actions actions   0 recs

I was just thinking...

someone either sucking one year then improving the next or vice versa. Also someone like Vizquel was he over/underrated?

www.buhnerbuzzcuts.blogspot.com

by ghostsalmon on Dec 14, 2008 10:54 PM PST reply reply actions actions   0 recs

Please use the reply feature.

Vizquel was and remained a pretty good defender for an absurdly long time. He was probably correctly rated.

As for others, Yuni going rapidly downhill is an easy example. As for getting better, you’d have to be looking more at young players or players shifting to a new position. Defense degrades from an early age.

by Matthew on Dec 14, 2008 10:57 PM PST to parent up reply reply actions actions   0 recs

UZR never loved him

but yeah. As for improvement, Jeter had a good year (read average) defensively according to UZR PMR and Dewan.

by Bearskin Rugburn on Dec 14, 2008 11:18 PM PST to parent up reply reply actions actions   0 recs

Vizquel could be both

He’s not Ozzie Smith, like the MSM says, but UZR loved late 30s early 40s Vizquel, so I have to imagine his younger self was +10 – +15 annually.

by JI on Dec 14, 2008 10:58 PM PST to parent up reply reply actions actions   0 recs

Wow

I was going through the 02 Indians’ UZRs on account of Vizquel rated a -8 that year looking for clues. Milton Bradley was a +5 CF. Oh, what could have been.

by Bearskin Rugburn on Dec 14, 2008 11:23 PM PST to parent up reply reply actions actions   0 recs

which Milton or Vizquel?

cause Omar nets -1 for that three year stretch. Could be because overall SS talent was high that year, and that’s an issue I’ve been kinda struggling with for a while (see above). Whatever, if anything it shows the limitations of these metrics and the value of evaluating fielders the way they do for the fielding bible awards.

by Bearskin Rugburn on Dec 14, 2008 11:31 PM PST to parent up reply reply actions actions   0 recs

Vizquel

Bradley had good speed at one point, it’s not crazy to think that he was between 0 and +5 when he was young.

by JI on Dec 14, 2008 11:59 PM PST to parent up reply reply actions actions   0 recs

Just curious...

Would Yuni losing weight help his defense or is he just a lost cause at SS?

by Fin on Dec 15, 2008 2:11 AM PST reply reply actions actions   0 recs

Pitchers and wins above average

Can I simply use runs above average (based on pBAA, or FIP*IP/9 or whatever my runs above average metric is) divided by 10.5 to figure the wins above average for a starting pitcher, or does something else need to be taken into account? How many runs/IP is replacement level for starters? For relievers?

What’s the proper way to account for high leverage for relievers?

by philosofool on Dec 15, 2008 9:00 AM PST reply reply actions actions   0 recs

What are the thoughts on "The Book, Playing the Percentages in Baseball"

I am going on vacation nest week and wanted to add it my read list, but if there are better books let me know.

I am no longer in Spokane, but I think I'll keep the name anyway.

by InSpokane on Dec 15, 2008 9:09 AM PST reply reply actions actions   0 recs

There are no better books.

I like using semi-colons; they make me feel smart.

by Llewdor on Dec 15, 2008 9:45 AM PST to parent up reply reply actions actions   0 recs

And just to clarify. I am going on vacation next week.

I am no longer in Spokane, but I think I'll keep the name anyway.

by InSpokane on Dec 15, 2008 10:41 AM PST to parent up reply reply actions actions   0 recs

The Book is very mathy. It's not an easy read, by any means.

If that’s a problem, ask for other suggestions.

I like using semi-colons; they make me feel smart.

by Llewdor on Dec 15, 2008 10:56 AM PST to parent up reply reply actions actions   0 recs

Agreed. It's not the first book on the subject I would try to read.

I have around as a reference, but I’ve never been able to just sit down and plow through it.

by acblue on Dec 15, 2008 11:08 AM PST to parent up reply reply actions actions   0 recs

The Book

I agree that The Book won’t necessarily be an enjoyable experience as you are reading it, but it should be satisfying in the end. It’s like vegetables. I would recommend The Hardball Times Annual (any of the last three were excellent… the earlier ones are also good) before reading The Book.

by tangotiger on Dec 15, 2008 12:28 PM PST to parent up reply reply actions actions   0 recs

I think it's completely indispensable.

It just assumes a higher level of understanding of the underlying concepts (as it absolutely must to serve the purpose that it serves) and isn’t really intended to be read for pleasure by most people.

by acblue on Dec 15, 2008 12:41 PM PST to parent up reply reply actions actions   0 recs

I think it all depends on how fluent you are with numbers.

The Book was my first real foray into truly advanced statistics and I really enjoyed it, but I’m a math major.

---
Juuuust a bit outside!!
http://www.rightfieldbleachers.com

by jhmoore on Dec 15, 2008 3:34 PM PST to parent up reply reply actions actions   0 recs

Yeah, if you can follow numbers relatively well you should be fine

I suggest maybe reading the “toolshed” chapter (that’s the first one) twice, because if you can follow that chapter, the rest of the book will make much more sense, since most of the results in the book are derived from those tools somehow.

---
Juuuust a bit outside!!
http://www.rightfieldbleachers.com

by jhmoore on Dec 15, 2008 4:37 PM PST to parent up reply reply actions actions   0 recs

How quickly does a team's defense change?

If I know a team has a good defense this year, what is the chance it will have an average defense next year? How often does the defense stay good? How much does defense bounce around? Is it cyclical? How well does it correlate to team age (which usually is cyclical)?

by Edgar for Pres on Dec 15, 2008 11:57 AM PST reply reply actions actions   0 recs

Dude. Check out Tampa 07 and Tampa 08

-54 UZR to +69. That’s… that’s a lot of wins on defense alone.

by Bearskin Rugburn on Dec 15, 2008 12:10 PM PST to parent up reply reply actions actions   0 recs

Also

Tigers 07 to 08 for the opposite direction. But it’s all correlated with major personnel changes, if you’re asking how much defense can fluctuate with the same players, I think it’s actually quite low, barring injury. The Phillies have had a good defense for a few years thanks to Rollins, Utley, Victorino and company.

by Bearskin Rugburn on Dec 15, 2008 12:18 PM PST to parent up reply reply actions actions   0 recs

There was also the Rockies' big decline from '07 to '08, mostly due to Tulowitski's injury and Brad Hawpe's general awfulness.

Every day I hear about Seattle sports' failures. Every night I fall asleep to the sound of my own tears.

by Benne on Dec 15, 2008 1:06 PM PST to parent up reply reply actions actions   0 recs

Actually, upon closer inspection, the Rox weren't all that great in '07, either.

-3.4 team UZR, good for 23rd in the league. It’s funny how much the MSM can pound assumptions and predetermined reputations in your head.

Every day I hear about Seattle sports' failures. Every night I fall asleep to the sound of my own tears.

by Benne on Dec 15, 2008 1:10 PM PST to parent up reply reply actions actions   0 recs

FWIW, again, UZR is just one measurement

and one year’s worth of data, yada yada yada

by Matthew on Dec 15, 2008 1:12 PM PST to parent up reply reply actions actions   0 recs

Of course, no disagreement there.

Can anyone provide me a link to PMR? One of these days I’ll subscribe to Bill James’ site so I can get +/-.

Every day I hear about Seattle sports' failures. Every night I fall asleep to the sound of my own tears.

by Benne on Dec 15, 2008 1:15 PM PST to parent up reply reply actions actions   0 recs

Thanks.

Every day I hear about Seattle sports' failures. Every night I fall asleep to the sound of my own tears.

by Benne on Dec 15, 2008 1:30 PM PST to parent up reply reply actions actions   0 recs

Team UZR should be pretty accurate though right?

I thought it was just player UZR that was very variable.

by Edgar for Pres on Dec 15, 2008 1:17 PM PST to parent up reply reply actions actions   0 recs

Defense question

UZR figures are in runs, while Dewan’s +/- numbers are in “plays.” From what I understand, a play is worth roughly 0.8 runs on average, but is there a difference in the run value of an outfield play compared with an infield play?

Basically, when we’re looking at Dewan’s numbers, is a +15 outfielder saving the same number of runs as a +15 infielder.

by Teej on Dec 15, 2008 1:44 PM PST reply reply actions actions   0 recs

It seems like there would be a pretty dramatic difference within IF

A 2B/SS play usually would result in a single while a 1B/3B would often result in a double. This might only be worth 0.01runs but I could see a play at 3B being worth more that 0.8 maybe.

by Edgar for Pres on Dec 15, 2008 2:03 PM PST to parent up reply reply actions actions   0 recs

If you had to judge a player's season by one stat...

What would be the best to choose for hitters, and then the best for pitchers?

www.raysprospects.com
Trade for Billy Butler!

by Imperialism32 on Dec 15, 2008 2:14 PM PST reply reply actions actions   0 recs

And yes, I realize using only one stat is almost always a bad idea

It’s just going to be a lot easier for what I’m planning on doing to use one pretty good stat.

www.raysprospects.com
Trade for Billy Butler!

by Imperialism32 on Dec 15, 2008 2:16 PM PST to parent up reply reply actions actions   0 recs

actually

If you chose from among the several good metrics for hitting and pitching performance, they’re mostly in agreement. With an entire seasons worth of data, wOBA, EqA, and GPA are all quite good. wOBA is theoretically the most sound (as I understand these metrics) but in practice each of them gives very similar results. Same with xFIP, FIP, tRA* and tRA. (FIP and tRA tend to give the pitcher more credit for his circumstances than he deserves though.)

For defense, the very best thing you can do is take the average run value according to all the play-by-play metrics you have available (UZR, PMR, +/-). Defense is much more difficult to quantify and there are several models for doing it. Integrating all these models will probably produce the most reliable results. Using just one for defense is a bad idea.

(People will tell you I’m wrong about this, but I actually think that integrating info from FRAA and RZR is worth doing. If I were to set up a spreadsheet for this, I would take the average run value from the three PBP metrics, weight them .8 and add the average of RZR runs and FRAA weighted .2 as the best measure of a players skill. I won’t argue for that here, I’ll just throw it out and let people jump on me for it if they want to. Sometimes I learn a lot that way. :-))

by philosofool on Dec 15, 2008 2:56 PM PST to parent up reply reply actions actions   0 recs

I prefer Game-Winning-RBIs and Wins myself

After all, the most important thing in baseball is to win, right?

by Fett42 on Dec 15, 2008 2:40 PM PST to parent up reply reply actions actions   0 recs

tRA regressed, an estimate of a pitcher’s actual talent level. Based solely on yearly performance, i.e. does not make use of career stats.

by oc on Dec 15, 2008 4:48 PM PST to parent up reply reply actions actions   0 recs

It's like this...
tRA* does not consider a pitcher’s statistics from other years and leagues.

What does that mean?

Is that because you would have trouble trying to regress them back to a new league or something?

Graham prefers tRA as an evaluation tool over tRA* and I’m just wondering why. Does tRA* not do something that tRA does?

I don’t mean to sound like a ballsqueeze, I’m just trying to understand the whole ‘league-regression’ thing.

by oc on Dec 15, 2008 7:04 PM PST to parent up reply reply actions actions   0 recs