What's Gone Wrong With David Aardsma?
by Matthew on Jul 23, 2010 1:32 PM PDT
in Seattle Mariners Stats
Email
PrintThis is perhaps the start of a long series of posts. Or maybe not. I realize this rather implies a commitment to go through each player, but I am unsure as to how much this will interest me if the reasons end up getting repetitive. Anyways, my goal here was to take a fresh look at David Aardsma and see what has gone wrong.
Aardsma installed some hope in us of becoming a useful bullpen cog after his stellar 2009 season. I do not believe that many people fully trusted Aardsma. In fact many people noted that they expected Brandon League would eventually supplant Aardsma as the closer this season. Still, Aardsma was counted on to be another above average hard-throwing righty in a bullpen shaping up to be defined by that mold. He has not delivered on that as reliever volatility has again taught us a lesson with a swift boot to the nether regions.
Are there any underlying shifts in Aardsma's effectiveness that is driving the higher ERA, FIP, tRA, etc? To determine what has gone wrong with David Aardsma we should first point out what has not gone wrong. The first piece that I look with pitchers is information on their individual pitches. I like to note any changes in speed (might indicate an injury) or any changes in how often they throw each pitch (might indicate a changing game plan or lack of confidence). In Aardsma's case both his pitch speeds and his pitch rates are fairly stable from their 2009 figures. For all the complaining about his nothing-but-fastball approach, Aardsma has actually thrown a few more sliders this season though it still is just a paltry 9% of all pitches thrown.
If there is nothing wrong with the pitcher, are the hitters reacting differently to him? This is where I move on to where the pitches are located and how often the hitters are swinging and making contact. With Aardsma it is just more of the same however. Hitters are swinging just as often this season and though they are making contact a little more often, it is not a dramatic difference. Aardsma is throwing fewer pitches in the strike zone, but he is throwing more first pitch strikes which helps to offset that. Last season Aardsma recorded 2.35 strikeouts for each walk and hit batsmen. This season that is down to 2 flat but over just 133 batters faced, that sort of fluctuation is minimal and is driven mainly by the two hit batters compared to zero in 2009.
The final general piece to the pitching puzzle is to investigate the batted ball rates. This offers clues to pitch location or possible changes in pitch movement. When it comes to batted balls there is actually good news to be had. After developing his fly ball fetish last season, which we were all familiar with, Aardsma has upped his ground ball rate this year from 25% in 2009 to 30% in 2010.
So what's gone wrong? To the best of our current knowledge, the aspects that have actually gotten worse for Aardsma are outside of his direct control. Aardsma's strand rate (70%) has been poor for a high-strikeout reliever, but we do not have good evidence that is skill-based. The home runs have indeed regressed. While Aardsma's ERA, tRA and FIP have risen this season, it is almost solely due to those home runs, of which he has allowed all of four. Yes that is over twice the rate that he allowed last season, but last season was not sustainable. I believe that xFIP reflects the overall picture quite well. Aardsma's xFIP was 4.12 last year and is 4.18 so far this year. Aardsma has just been the victim of some bad luck.
16 comments
|
0 recs |
Do you like this story?
Comments
What the deuce?
I was thinking “I could have sworn he was throwing even MORE fastballs this year. Guess you just notice it more when he appears to be sucking.” so I decided to look at his pitch selection on fangraphs. I noticed that he had 7% XX (unknown) pitches this year, as opposed to only 3.2% last year. But then I started adding up the percentages, and all the pitch types in columns other than XX add up to 100%.
I’m assuming this isn’t a bug, since I haven’t looked at these charts all that much. Anyone know what’s up?
Mariners/D Broncos/BSU Broncos fan in Seattle
The first rule of Lookout Landing is...
He's not a "victim of some bad luck"
He’s not as good as his results last year, and his numbers this year are closer to the rest of his career than they are to last year.
He’s not a victim of some bad luck this year— he was the beneficiary of some good luck last year. His career strand rate is 72%, his career HR/FB is 9%. Basically what we’re seeing this year.
Point by point.
He’s not as good as his results last year
Nobody has ever said he’s as good as his results last year.
and his numbers this year are closer to the rest of his career than they are to last year.
What numbers? Without specifics, this is meaningless.
he was the beneficiary of some good luck last year
Again, nobody has ever said otherwise.
His career strand rate is 72%, his career HR/FB is 9%. Basically what we’re seeing this year.
No. It’s not. His strand rate is 3 points lower and his HR/FB rate is two points higher than his career averages, which aren’t useful of a baseline in the first place. Secondly, neither of those are primarily skill-based stats.
Aardsma’s RA stands at 4.88. Based on everything that we can see about him, that’s higher than it should be for reasons that are not his fault.
by Matthew on Jul 23, 2010 3:59 PM PDT up reply actions 2 recs
First, I apologize if my attitude isn’t conducive to good debate, as pointed out by johnbai below.
I brought up LOB% and HR/FB because those are the two “luck” stats you mentioned in the post (HR/FB indirectly through xFIP). I never claimed that these are skill based. I was specifically addressing the claim that Aardsma has been unlucky this year.
HR/FB LOB%
2009 4.2% 77.5%
2010 10.8% 69.5%
career 8.6% 72.6%
career ex 2009* 10.6% 71.1%
league avg ~10.6% ~71.4%
*I'm not saying it's valid to exclude 2009, I just did that to illustrate the point.
I’ll concede that he’s been a bit unlucky on the LOB%. However, his HR rate is in line with what we should expect, so if the bad results are HR-driven, as you suggest, then that component is not really a case of unluckiness, it’s just a result of an extreme FB pitcher giving up HR’s at the league average rate.
I agree that the RA of 4.88 is higher than what we should expect, and that 4.18 is more in line, so you are correct that he’s been unlucky.
We are dealing with small samples (31 IP) so it’s hard to get worked up over the components, but I’ll just mention here that his 4 IBB account for ~0.38 relief in his FIP/xFIP, which is over half the delta between his RA and xFIP.
In conclusion:
1. He has been unlucky. I had a knee-jerk reaction when you said that, because he hasn’t been nearly as unlucky as he was lucky last year.
2. It’s not the HR’s. It’s partly strand rate, and partly more IBB than we should expect going forward.
First, use the subject line. Always.
Secondly, IBB do not count toward FIP or xFIP.
Thirdly, no it is the HRs. League average HR/FB is lower for RPs than for a sample including all pitchers.
Yes, FIP and xFIP ignore IBB, but
an intentionally walked runner can still come around to score, so this would affect RA. If a pitcher intentionally walked runners at a higher rate than league average (the constant added to the FIP calc should restore league average IBB rate) we would expect this to show up in the FIP/xFIP vs ERA spread. When I said “relief in his FIP/xFIP” I meant relative to RA.
I’m calculating the HR/FB rate for RP over the last 3 years at roughly 0.7% lower for relievers than for all pitchers. I can imagine a number of factors which contribute to this. Do you happen to have a link to a study on this effect? I couldn’t find anything very detailed.
If Aardsma is unlucky on HR/FB this year, I still don’t think it’s by a whole lot, but I guess I can admit that he has been a bit worse than average in that regard as well.
Realistically, a lot of random stuff happens over 31 innings that doesn’t get washed out in the stats. I just happen to think that a 4.88 ERA vs a 4.22 FIP isn’t a big enough deal over this sample size to call it “unlucky” so much as normal variation. But I guess the counterpoint is that most of the variation is luck, so if it’s goes against you, you are by definition unlucky. Fair enough.
Dear Mango,
I actually agreed with most of what you’re saying, but your attitude isn’t conducive to good debate. Directly contradicting Matthew rather than saying that you have a “different take” might spark better discussion.
It would be interesting for me to read about, for example, an explanation of why a 69% strand rate IS significantly different than a 72%. And what does a 9% HR/FB rate really mean for a short inning sample vs. a 7% HR/FB. Do these numbers really mean more than 2-3 runs over Aardsma’s season? And if so, do they account for the dramatic shift in his perceived performance this year?
by johnbai on Jul 24, 2010 11:46 AM PDT up reply actions 1 recs
Doesn't have to be a long series...
I wouldn’t be worried about that. A lot of the articles would end up the same conclusion. What’s wrong with him is a major league franchise decided he was something other than AAA fodder… or something along those lines. However, most of the articles in a series such as this, in a season such as this, would provide great analysis and a bit of a map to avoiding the mistakes of a lost season. So, carry on as far as you like, Matthew, I say.
------------------------------------------------------------------------
Just North of Wrigley Field
Actually, I think other teams notice this too.
If they wanted him before they probably still want him. I think the real issue is whether or not other teams think he is worth the risk. A fly ball prone, hard throwing righty is always a risk, because home runes are always more of a risk with that type of pitcher. I think you can expect more bad luck from a pitcher like this than good luck, if that makes sense. especially in a reliever.
...and now I'm here
Would you prefer your runes elsewhere?
...and now I'm here
Situational data?
I would be interested to know what the average lead is that he’s been brought in to save, last year and this year. As a function of scoring fewer runs, you would expect our 9th inning leads to be smaller on average, right? Obviously he’s regressed in the HR/FB category, but I think it feels worse to us because it’s amplified by the fact that a regression of X has resulted in an increase in blown saves of something a lot more than X.
The whole team has been a victim of bad luck.
It must be payback for the good luck of last year. Honestly though I think a lot of these teams woes come from just losing some good games near the beginning of the season that they really should have won. A true mess of a season in almost every aspect has to wear on a players attitude and confidence. Those things go away and performance goes along with it. No other explanation for so many to be performing below their norms.
His GB% is up, but his strikeout rate is down
I’m not sure that for David Aardsma, an increased GB rate is a good thing. I’m also not sure it’s a bad thing, but without seeing some corresponding increase in effectiveness, I can’t think we can actually look at his increase in GB rate and say it’s an improvement.
Of course, with the limited amount of hitters a short reliever faces, it’s hard to look at any of the results and have much confidence that we’re seeing anything that tells us a lot. I would have to second your overall belief that the majority of the runs scored difference from last year is just good old random occurrence. Sometimes you’re the windshield, sometimes you’re the bug, and that’s especially so with relievers.
by nathaniel dawson on Jul 25, 2010 7:09 PM PDT reply actions
Comments For This Post Are Closed
Secondary Sidebar
User Tools
FanPosts
Community blog posts and discussion.
Recommended FanPosts
Recent FanPosts
In Association With
Big League Stew - MLB - Yahoo! Sports
- Marlins agree to unretire No. 5 for Logan Morrison, who will honor his father’s favorite player
- Weatherman Derek Holland does Dallas TV
- Ask Alex: Will Julio Teheran or Matt Moore win rookie of the year?
- Ku Klux Klan, umpires and bowling: Why the minor leagues tossed out Jim Evans academy
- The Cardinals Hall of Fame can now be found at Bill Clinton’s library in Arkansas (Huh?)
Certain photos copyright © 2012 by Associated Press or Getty Images. Any commercial use or distribution without the express written consent of Associated Press and Getty Images is strictly prohibited.
