Statistical reasons behind the slump [Archive]

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PaulieIsAwesome

05-04-05, 11:28 AM

Just to get people thinking a little, what are the main reasons behind the Yankees early season slump, from a statistical perspective?

First off, their Pythagorean win expectation is .500 right now. Of course, that comes from winning a couple of games by 10 runs and losing a couple of close ones. Then again, that should balance out over the season.

The Yankees give up a lot of runs. They have given up 18 runs more than an American league average team in the same number of innings, good for third to last (ahead of only TB and KC) in Runs Allowed Above Average.

Why?

The actual pitching is alright. The Yankees Fielding Independent Pitching so far this season is a respectable 4.24. This is only 9th in the American league, but, it's not terrible, being good for a little above AL average (TB's 5.55 FIP brings down the average.) Only a couple of FIP runs separate the Yankees from the 4th spot in the AL.

And yet. The team ERA is 4.72. This means that the defense is wretched. Awful. BP's Defense Efficiency Ratio has them at last in the league right now, as does hardballtimes. This is the key for the bad runs allowed.

In terms of who to particularly blame for the defensive woes, BP's defensive pages (the only ones I can find so far) show first base at 4 runs Below Average (all 3 who have played there at considered below average), A-Rod as 4 runs below average, Bernie as 2 runs below average. Actually, this pretty much says the Yankees have average D, since they say Jeter is +3 and Womack (!) is +5. Some of this might have to do with the earlyness of the season putting gremlins in BP's regressions.

That leaves the offense. The Yankees are 2nd in the league in OBP. They are 4th in slugging. They are pretty efficient, since a run estimator I devised says they should score 135 runs with that OBP and SLG, and they've scored 139. I can't exactly compute OPS+, but it's very close to 109 or 110, good for about second in the league.

So, it looks evident that it is the defense that is most to blame. I can look at whether the bullpen or rotation has pitched particularly poorly, but from these numbers it's clear the weakest leg is defense.

Now to fixing the problem.

Prickly Pete

05-04-05, 05:52 PM

ChewieTobbacca

05-05-05, 04:10 AM

Whats our BABIP?

Last I saw 10 games ago our BABIP was an amazing 60 points higher than league average

PaulieIsAwesome

05-05-05, 07:41 AM

Interesting analysis. The teamwide defensive efficiency stats you cite probably have some merit -- even though it's early, we're talking about 600-700 "balls in play," so that's a decent sample size. As you suggested, it's probably much too early to read into the individual defensive stats.

Care to share?

Sure. Pretty simple. Just ran regressions on OBP and SLG with Team Runs Scored over the last 10 years on AL teams, as part of running regressions on Wins versus Team ERA and OPS. The formula for 162 games is 3240*OBP + 1540*SLG-950.

To answer Chewie's q, are you asking about our offense or our pitching? BABIP for our pitchers will be very closer to 1-TeamDER, since TeamDER on BP's site is the balls in play turned into outs (1-BABIP) adjusted for Park, and with an adjustment for team errors. Given our DER, we're almost certainly miles below average (or above average in the bad sense: we have a very high BABIP.) Yes, the Yankees BABIP is the worst in league at .344, compared with league average of .295.

ieddyi

05-07-05, 09:33 PM

I'm not sure exactly how the defensive efficiency number is calculated. I've watched almsot all of the games, and I agree the defense is horrible. BUt a lot of the balls in play have been scorched (especially in TB on that rubber field- almost like they made it out of ground up super balls)- balls that you couldn't reasonably expect to be caught. It seems like that stat could be fooled by not differentiating between balls that could reasonably be expected to be caught and screamers that could only be caught if hit directly hit at someone. If a pitcher is constantly giving up that kind of hit ball, shouldn't more of the "blame" be placed with him rather than the fielders?

gurgie

05-07-05, 10:51 PM

I think THBT has a cool chart that tracks line drives for both hitters and pitchers that is a preaty good way to tell how hard the ball is being hit. it also shows one problem with only looking at balls in play turned in to outs. unless these defensive formulas take in to acount what type of hits (liners or fly balls) they need to be taken with a grain of salt

PaulieIsAwesome

05-07-05, 11:25 PM

You guys are certainly right. The Yankees pitching staff has a .189 Line Drive% (see hardballtimes.com) compared with the league average .172. This is 3rd worst in the AL (interestingly enough, the bottom 2, BOS and OAK, have ERA's of 4.12 and 3.98 respectively, so LD% doesn't correlate that well with ERA.) This probably explains some of the terrible DER. But, I don't think it explains all of it.