The One About the Gyroball

In an ongoing series on digging into the PITCHf/x data provided by MLBAM's Gameday sysem, this week in my Schrodinger's Bat column I take a look at Daisuke Matsuzaka. The system has captured 586 of his pitches over six starts and so that gives us a pretty good sample to work with as shown in the following table:

Start              Pitches   IP  H  SO  BB ER
4/17 at Toronto        105  6.0  3  10   3  2
5/9 at Toronto         102  7.0  5   8   3  1
5/25 at Texas           85  5.0  7   6   3  5
6/5 at Oakland          55  7.0  7   8   2  2
6/22 at San Diego      126  6.0  5   9   5  1
6/27 at Seattle        113  8.0  3   8   1  1

Interpreting the data to identify his varied repetoire is somewhat more difficult than it is with pitchers who throw "only" three or four pitches but I was encouraged that it could still be done with some degree of accuracy (as checked against the Inside Edge data made available on ESPN Insider). In the article I identify his fastball, slider, cutter, curve, changeup, and forkball/splitter. His hard sinker, or shuuto, apparently behaves much like the forkball and so some of these may be included in the forkball category.

So what about the gyroball? Well, you'll have to read the article to see if the pitch remains a mystery.