Monday, April 21, 2008

98 On The Black

John Walsh at the HardballTimes wrote a very interesting article about the effectiveness of the fastball. He broke the strike-zone into sections and looked at the result of fastballs at various speeds. A strike thrown down and away from a righty pitcher to a right-handed batter was up first: "Let me say that in plain English: An 87-mph fastball in this part of the strike zone is every bit as effective as a 96-mph heater." Here's the breakdown for each zone:

It's only on a pitch inside (especially thigh high) that throwing harder makes a big difference. To try to figure out why speed doesn't have as large an effect on pitches down and away, Walsh looked at various factors, one of which was called strike percentage (they are all technically in the strike-zone).
"Around 30 percent of all taken pitches in the low-and-away zone are called balls and the faster the pitch, the higher chance it has of being called a ball. Remember, essentially all these pitches are actually in the strike zone and should have been called strikes. So, here we see a definite disadvantage to throwing hard—you have a greater chance of a bad call from the umpire. That sucks doesn't it? Ninety-eight mph heater at the knees on the outside black: BALL! calls the ump. Same exact location, but now it's thrown at 86 mph: STRIKE! Maybe this is the reason that guys like Tom Glavine, who work the outside corner with soft stuff, seem to get more than their share of close calls."
The difference in inside vs. outside is largely the byproduct of home run rate:

"This is the percentage of balls in play resulting in home runs. Keeping in mind that we're looking at small sample sizes here, we see that a large part of the dependence on speed for inside pitches comes from the ability of hitters to drive the slower pitches out of the park. Outside pitches seem more difficult to hit for homers, no matter what the speed."
I've often heard it said that a large reason that velocity is a good indicator for success is that it helps make up for mistakes that a pitcher makes. This appears to be backed up by the data - if a pitcher misses at 91 it is more likely to get him into trouble than if he misses at 96. Also, Leo Mazzone's "locate the fastball low and away" philosophy makes a lot of sense - if a pitcher can execute it consistently. So, to sum up:

" 1. fastballs outside don't depend much (if at all) on speed for their effectiveness;
2. conversely, inside fastballs are more effective the harder they are thrown (this one I already knew);
3. most of the observed effect appears to come from home runs: outside pitches are rarely hit for homers and when they are, a fast pitch is as likely to be hit out of the park as a slow one;
4. a pitch thrown hard is more susceptible to the ump's bad call than a soft toss. "

Pitch/FX data is the next major advance in sabermetrics, and I'm am keenly awaiting the insights that can be drawn from it.

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