More on Adjustment Periods

by Jeff Sullivan on Apr 27, 2005 8:35 AM PDT in Seattle Mariners Regular News

Most recent performance before switching leagues:

.272/.340/.438

First two months in new league:

.269/.340/.429

Rest of the season in new league:

.272/.340/.449

The numbers pretty much speak for themselves - at least as far as our 78-player sample is concerned, the group picked up where it left off in terms of hitting for average and getting on base after switching leagues, but it took a little while for the full power to show up. The group saw an 11% increase in isolated power after its firs two months, which - while not very large - is still something.

It's worth mentioning that the group put up worse numbers in its second month in the league league than in the first month, perhaps suggesting that pitchers are able to adjust to new hitters faster than hitters are able to adjust to new pitchers. The difference isn't very large, though, so that's a dangerous conclusion to reach.

How does this relate to Adrian Beltre and Richie Sexson? After all, they're both off to slow starts, Beltre in particular. While we can't explain away all the struggles that each hitter has had so far, what we can do is point out that the data suggests that an adjustment period does exist, however small it may be. They still need to start getting on base - last night was a good start towards that end - but it certainly helps to know that all this talk about learning new pitchers isn't just hot air.

If we're still looking at two underachieving sluggers in July, then it's time to worry. Until then, though, be patient.

Tweet Comment 5 comments | 0 recs |

Do you like this story?

Comments

tight fit?

What kind of standard deviation are we looking at for that average? Maybe there is some connection between power hitters adjusting more slowly then contact hitters, which would seem to make sense intuitively.

by gumbostu on Apr 27, 2005 10:24 AM PDT reply actions

Re: tight fit?

All those numbers are well within a single standard deviation of each other. When you're talking about rate stats in baseball, you need an enormous data set in order for the standard deviations to actually mean anything, which is why they're rarely used (to the best of my knowledge).

by Jeff Sullivan on Apr 27, 2005 12:06 PM PDT up reply actions

baseball stats

I work with stats a fair amount in my job, and I think that one thing that baseball stat guys often do it look at means a lot, specifically when they are focusing on a phenomenon instead of focusing on a single player.

Your analysis is good, but the reason why it is not very conclusive is that you might be lumping groups on players together, which tends to even out the mean.

What you are interested in is how players adjust to switching leagues. From a common sense standpoint, there are players who struggle with this, and players who don't. If you just work with a mean of how players did before and after, the ones who do well will basically offset the ones who don't. Thus, instead of looking at means, it might be more interesting to look at what types of players are doing poorly and which aren't.

It could be really illuminating to categorize players and see what happens. For instance, do guys who get by on preparation (like, for instance, Nick Johnson, Rich Aurillia, Jeff Cirrillo), guys with 'old-guy' skills (Delgado, Thome, Sexson), table-setters/leadoff types, free-swingers, toolsy players, ect. have different experiences switching leagues. These differences in approach and skillsets might have a huge impact on how players do when they change leagues.

Whenever you get inconclusive stats, it is worthwhile to stop and consider what types of factors could be influencing your numbers. What looks like a high degree of variability could just be a bi-modal distribution, and you just need to find out the best way to split up the data to find the interesting patterns.

by Jerry on Apr 27, 2005 10:38 AM PDT reply actions

asdf

I'd like to see your numbers split out to judging only those switching from the NL to the AL. "Common Wisdom" (whatever that is - misperception?) says that the NL is more fastball oriented while the AL is more offspeed oriented...

If this were true, (a big IF), then it would follow that those players switching to the AL might have a tougher time than vice versa and that imbalance would effectivley account for your numbers.

by John @ Lookout Landing on Apr 27, 2005 7:08 PM PDT reply actions

Re: asdf

There's all kinds of stuff that I'd like to do with this data - including what you mentioned, and what Jerry mentioned - but the sample is already so small that breaking it down further really wouldn't provide any meaningful data.

You'd have to go back earlier than 2000, and I don't have access to those numbers.

by Jeff Sullivan on Apr 27, 2005 7:13 PM PDT up reply actions