Wednesday, August 8, 2012

A Tale Of Two Similar Pitchers

Here are two pitchers that have both pitched for the same team. Which pitcher would you rather have on your team? Since 2009 one of them has struggled but before then he was extremely productive. The other pitcher debuted in 2006 and is currently one of the best pitchers in baseball. Here are their stats:

Pitcher A (2002-2009):

K%: 18.80% BB%: 6.90% HR/FB: 9.30% GB%: 43.2%

ERA: 3.81 FIP: 3.83 xFIP: 4.00 WAR: 31.3

Pitcher B (2006-2012):

K%: 21% BB%: 6.50% HR/FB: 7.50% GB%: 33.6% 

ERA: 3.19 FIP: 3.59 xFIP: 4.04 WAR: 27.4

If you haven't figured out who they are yet, you'll find out after the jump.

Player A is John Lackey while he was with the Los Angeles Angels. Player B is current Los Angeles Angels ace, Jered Weaver. It may seem surprising to some, but not long ago John Lackey was one of the best pitchers in all of baseball. From 2005-2007 there were only a handful of pitchers that could say  they were better than the Angels ace. Some other pitchers that can claim they were better or were just as good include Brandon Webb, Johan Santana, and CC Sabathia.

I used FanGraphs handy filtering system on their custom leaderboards (HIGHLY recommended) and took a look at all pitchers who had a K% >= 20%, a BB% <= 8% and a FIP <= 3.40 to get a deeper look at Lackey.

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His 3.34 FIP during that time is a little high for a number one pitcher, ideally you'd want it below 3.30. His 3.88 SIERA is the highest of the bunch though and that is definitely worrisome. He did do a goob job striking out batters, but his BB% was tied for last with Roger Clemens. He also did a good job limiting strikeouts, his HR/9 was one of the best in the group. Lackey also posted solid numbers in his first three seasons (2002-2005) as well as in his last two seasons and first season in Boston (2008-2010).

For some reason Lackey has really struggled in Boston though. In two seasons he's seen his SIERA spike all the way to 4.22 and 4.50. He's also seen his K% decrease the last two seasons as well. I'm not quite sure what the cause is because he hasn't lost any velocity on his fastball at (91 mph vFA) and he's a groundball pitcher. One would think that he would be fine in Boston.

I did the same thing with Weaver but I looked at his 2009-2011 seasons. The results are pretty interesting.

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Jered Weaver's 3.42 FIP during his three year stretch has actually been worse than Lackey's. Weaver does have a better SIERA then Lackey, though. Weaver also has struck out more batters and has walked less, albeit it's been only .5% less. In terms of fWAR though Lackey was the more valuable one though. Lackey was worth two more wins than Weaver was.

I addressed it a little above, but again, why did Lackey start struggling so bad when he reached Boston?  I looked at FanGraph's park factors to get a better idea. At Fenway both left handed and right handed batters have a bigger advantage when it comes to doubles. Other then that I couldn't find much. It's entirely possible that Lackey just started to wear down as he reached and passed age 30. That doesn't mean that will happen to Weaver though. While Lackey and Weaver aren't entirely similar to each other they do have a lot of traits that the other has. It will be interesting to see how Weaver ages, especially since he will be in Los Angeles for the foreseeable future.

6 comments:

  1. This is a cool comparison. Never would have thought the two shared common stats. Sidenote of Lackey, his GB% decreased to 40% in 2011. Perhaps part of his slide is due to a flaw in his mechanics that is leaving the ball up more and hitters are hitting more drives/fly balls? Chance for further analysis! Good article!

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  2. Thanks man. I actually didn't think of the actual idea though. Anthony (who made one post/comments brought it to my attention. He's the guy I'm gonna do the podcast with! That's a good point, maybe I can look into that sometime.

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  3. Well done, put it into better words than I could have

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  4. A few comments here:

    1) Those cutoffs for rotation slots are current era, one-year numbers. 05-07 was a higher run environment, so you'd have a higher threshold for ace status. Also, multi-year stretches converge towards the mean, making for a lower standard deviation and different cutoffs.

    2) Make sure you include IP totals when you talk about WAR. The reader wouldn't know if the WAR totals are skewed because Lackey threw more innings during his 3-year stretch. Turns out Weaver had 20 more IP, which widens the gap a bit further between the two.

    3) When talking about past results, don't call predictive stats like SIERA worrisome. That is like saying you're worried about someone's BABIP from five years ago; the next phase of his career is already over, so you don't have to predict anything.

    4) When filtering out categories, don't say someone is last in that stat. Lackey still had a below league-average BB rate during that stretch. Also, you should expect him to be the worst of the bunch when you cherry-pick the filter guidelines.

    5) 2011 was really just a freak year for Lackey in all senses. First, the park factor difference between LAA and BOS is 99 to 105, fairly significant. Second, moving from the AL West to AL East results in facing much better offenses. Third, he had the major distraction of his wife battling cancer and the ensuing divorce talks. Also, he ended up having TJ, so he was probably hurt for a stretch of the year, which won't help the results.

    Ok, that was a lot more than I thought.

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  5. Thanks for all of that. Even though it was a lot, it definitely helps.

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