Brian Wilson's Pitch Locations

Brian Wilson was a huge factor for the San Francisco Giants last year. During the regular season he led the Giants into the playoffs with a league-high 48 saves and a sparkling ERA of 1.81. He didn't allow an earned run in 11.2 postseason innings, permitting just five hits with 16 whiffs. Plus six more saves. And a World Series Championship.

Just for fun, I thought it might be interesting to take a look at how Brian Wilson starts off batters on his first pitch to them. The difference between what Wilson does against righties and lefties is remarkable. The first chart here is Wilson's pitch locations on an 0-0 count against righties in 2010.

He comes right at 'em. He wants that first pitch strike; he threw the first pitch in the strike zone over 60 percent of the time in 2010. And, as you can see from the picture, his most common location is right down the middle.

But it's totally different against lefties. Here's the chart:

He only threw strikes about 40 percent of the time and most of the pitches were on the outside corner (usually out of the zone). Belt high, for the most part.

What a different approach for Wilson based on where the batter stands.

This is an example from the Pitch Locator charts on the new iPad/iPhone app, Bill James Baseball IQ, that will be hitting the App Store very soon. A couple of weeks ago we presented a few examples from the K Zone chart on the app for Carlos Pena and Carl Crawford. When we ran that example, we had a couple of people in the sabermetric community question the validity of the pitch location information provided by Baseball Info Solutions. Let me take a moment and address that.

One of the questions that has come up is: How can the video scouts who track pitch location data at Baseball Info Solutions (BIS) be as good as Sportvision's very cool Pitch F/X technology that tracks pitch location using hi-tech camera angles. In short, how can a human being be as good as the technology?

The answer is that, at BIS, it's not simply human vs. technology. The equation at BIS is that technology PLUS human review is much better than technology alone. Let me explain. Pitch F/X technology is a huge step forward in baseball analytics and the pitch location data it provides is excellent. But not perfect. At BIS, they take it a step further. Thanks to the fact that Pitch F/X data is publicly available, when BIS video scouts review video to determine pitch location, they also have information about how Pitch F/X plotted the location. The video scout reviews both the actual video of the pitch and the Pitch F/X location to determine where the pitch is located. In essence, pitch location charting at BIS enhances the charting done by Pitch F/X to come up with what BIS believes to be the best data possible, a kind of Enhanced Pitch F/X.

As a way to test this, BIS conducted an impartial study. They selected the 100 pitches from their database of the 2010 season that represented the biggest discrepancies in pitch location between BIS data and raw Pitch F/X data. They then meticulously reviewed video once again on all these pitches. The video scouts reviewed the pitch location and selected the data source, either BIS or Pitch F/X, that they believed best represented the true location.

These impartial video reviewers chose BIS plotted pitch location data 55 percent more often than the raw Pitch F/X location as the correct location. The details: 59 choices for BIS pitch location (Enhanced Pitch F/X), 38 choices for the raw Pitch F/X location, 2 pitches that Pitch FX has since corrected, and one pitch where neither location was close.

While these results still leave room for improvement, they do indicate that the BIS method of enhancing pitch location data improves on the charting of raw pitch location by itself.