07 May 2007

The Tsao of Baseball

by Joshua Worley

The deepest reasons of baseball are ineffable. Why did Chin-hui Tsao blow up yesterday? Why has Betemit hit two home runs after going 7-56 with no home runs previously? There is no real answer to these questions, except an observation: what precedes is no sure indicator of what will come.

And yet, if we know what to look for, we can find clear trends in baseball that explain a season, a career, an era. I will never forget first reading about Defense Independent Pitching in Rob Neyer's column, when he introduced to a widespread audience Voros McCracken's discovery that pitchers had almost no control over batting average allowed on balls in play. The claim, now widely confirmed, was that the best way to predict a pitcher's future ERA was not by looking to his past ERA, but with a model based mostly on his strikeouts, walks, and home runs allowed. To know what will come, over the long-term, we need to know precisely what to look at in what happened before.

I suggested before the series that the Braves were winning more than losing primarily by hitting more home runs than their opposition; I also hoped that if the Dodgers could win or draw the home run battle they might take the series. Well, the Dodgers out-homered the Braves 2-0, and yet the Dodgers only won 1 of 3. We may see trends, but no single game is defined by them. Trends only work for the long term: they are of little use in the moment.

Let's breakdown Tsao's performance between yesterday and what preceded yesterday:

Bf -- SO -- BB -- H -- R
33 -- 7 -- 2 -- 1 -- 0
7 -- 1 -- 2 -- 3 -- 5

"Bf" is batters faced. In what preceded, hitters were 1-24 when they put the ball in play against Tsao. Yesterday, hitters were 3-4 when they put the ball into play. What explains this? Luck, apparently. That is more or less the answer given by the very successful model of Defense Independent Pitching.

So it turns out that strikeout rates are a very important indicator of future success. The common measure of strikeout rate is strikeouts per nine innings pitched. Here is a comparison of Tsao and Broxton:

Tsao -- 6.35
Brox -- 8.69

Tsao's is OK, Broxton's is excellent. His rate is 37% higher than Tsao's. Except it's not. Not if you look deeper. Tsao has been getting a lot more outs on balls in play than he really should have, even with yesterday's 3-4 against him. If he had been allowing a normal amount of hits on balls in play, then some of his lucky outs on balls in play would be hits, and he'd lose some outs recorded, and so to achieve his same number of innings pitched he would be forced to make-up those outs with more batters faced. He would have struck out some of those extra batters faced, and his strikeouts per innings pitched would go up because the total innings pitched hasn't changed. Or even more simply, when strikeouts-per-innings-pitched is the measure, a non-strikeout out hurts the rate, while a hit allowed is neutral to the rate. Does that make sense, at all?

Here is a comparison of Broxton and Tsao in terms of percentage of batters faced struck out:

Tsao -- 20.0%
Brox -- 24.2%

Broxton's rate is really only 21% higher than Tsao's. Tsao is both overrated and underrated, for the exact same reason! What a bizarre thing to happen. Whether he is underrated or overrated depends on how you look at him, in terms of hits allowed or strikeouts per nine innings. In my opinion, strikeouts per nine innings is not quite the right stat to look at to measure strikeouts because of these extreme cases. And yet that's what people usually look at, and to be fair it does pretty well.

No matter how strikeouts are measured, they are clearly important to pitcher performance. Are we to look at strikeouts as completely under the pitcher's control, and other kinds of outs such as groundouts as simply a matter of what the batter does? It can't be that simple, can it? Sometimes a pitch that will strikeout one batter will be hit by another one. Sometimes a pitch that would be missed by one batter will be hit weakly for an out by another. On Saturday Saito threw an outside slider that went for a nasty strikeout in several previous games, only this time was hit. What happened? A scouting report, probably, or a better hitter, or slightly worse break or location ... or maybe ... luck. I don't know.

Why did Wilson Betemit just hit two home runs in two at bats after starting the season 7-56 with no home runs? One theory might have to do with the promotion of Andrew LaRoche, though that wouldn't explain his first home run. So modify this to say that his benching lit a fire under him, and the promotion of competition turns up the heat even more. I don't accept either of these explanations.

Then was it just luck? Not entirely, because I think something did change between Friday and Saturday. Betemit hit rock bottom on Friday. He took two really hittable pitches in one strikeout, and this is the important point: he had to know it. He hit rock-bottom not just in his results, but in his approach, in what he was giving himself a chance to do. I'm guessing he thought, "This isn't working; I'm up there guessing or out-thinking things too much, letting pitches I have a chance to crush go by." I'm guessing he got himself back into a state where if he saw what looked like a juicy pitch, he would swing at it. He put himself back into a position where his natural skill could come through again, where he could get lucky again, and he did! He hit two beautiful home runs. The benching and the promotion of competition of LaRoche did not cause him to hit two home runs. The most connection I would grant between these things is that they were all set in motion by the same event, his hitting rock-bottom on Friday.

Why did Tsao blow up? The easiest answer is that he walked two, and only struck out one of seven, and that he got unlucky on the balls hit in play. Maybe he got a little unlucky on the walks, too. Was there a pitch that should have been called a strike, or normally would have been swung at? We can go around and around about what happened, but it's not worth it. By the end of the year, Tsao's performance on Sunday will blend with all his other performances to make the Tao of Tsao, the pattern that seems to tell us what will happen when he pitches, except when it doesn't. That's the way it is for every player; that's the way it is for baseball.

1 comment:

Charlie said...

You make some really good points. One of them that I take to heart is that we can always go deeper 'inside the numbers' to try and divine what's 'ability' vs. 'luck.' Strikeouts per batter faced *is* a better reflection of strikeout ability than K/IP. But then of course you could go deeper still, and examine quality of hitters faced, situation in the game, park factors, umpire, etc. There really is no limit. So we come back to K/IP because it's easy to calculate and, as you note, in the long run it communicates probably 95% of the info you need regarding K rate.

But all of this is maybe a long way of saying that sometimes watching the game, each play, gives you a better sense of how somebody did than just the line score.

For example, looking at Tomko's game Friday, the linescore would tell you he was pretty bad: six walks, four runs, and he didn't make it out of the fifth. But watching, I saw that he was facing a tough, disciplined lineup that would not chase pitches and was ready to whack anything over the plate. So Tomko did the best he could, trying to paint the black, maybe getting squeezed here and there, but battling. And if Juan Pierre could play center better than a high school kid, Tomko might have gone six or seven innings. So, just an example.