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A's Baseball

Balls in Play Average Revisited

Quick trivia: who hit the three home runs off Tim Hudson so far this year?

I enjoyed last week's foray into Balls in Play Average, and I thought I'd extend it beyond Barry Zito. Here are the averages for the 'Big Three':

BIPA

Mulder
2001 > .270
2002 > .258
2003 > .276
2004 > .257

Hudson
2001 > .272
2002 > .279
2003 > .246
2004 > .286

Zito
2001 > .275
2002 > .238
2003 > .233
2004 > .300

Team
2001 > .273
2002 > .274
2003 > .266
2004 > .282

Notice that the percentage of hits allowed on balls in play by the entire defense (the BIPA, that is) doesn't vary much from year-to-year. The loss of Mark Ellis has apparently hurt the A's defensive efficiency, but the variation is still small. But for Mulder, Hudson and Zito, the defensive efficiency while they're on the mound has varied wildly! It's difficult for the team defense to get that much better or worse from one year to the next, but the batting average allowed during a given pitcher's starts can change by 60 or 70 points.

What tells you a lot more about a pitcher is what he does in the at-bats when he doesn't allow the batter to put the ball in play: strikeouts, walks, home runs and, less significantly, hit by pitch. First strikeouts:

K rate

Mulder
2001 > .165
2002 > .184
2003 > .171
2004 > .165

Hudson
2001 > .185
2002 > .155
2003 > .167
2004 > .115

Zito
2001 > .227
2002 > .194
2003 > .153
2004 > .160

Mulder has been consistent, but both Hudson (in 2004) and Zito (in 2003) have shown an alarming drop-off in strikeouts. Falling strikeout rates usually mean poorer future pitching performance, and Barry Zito's 2003 numbers were low enough that most analysts predicted a poor 2004 for him. In fact, many analysts suggested the A's should trade Zito after 2003 while his value was high - higher than what they thought his potential was in 2004 and beyond. Clearly Billy Beane thought differently, perhaps for marketing reasons. Neither Mulder, Zito nor Hudson has had much variation in walks over the year, though Hudson and Zito have seen some surprising changes in their home run rates:

HR rate

Hudson
2001 > .020
2002 > .019
2003 > .016
2004 > .007

Zito
2001 > .020
2002 > .026
2003 > .020
2004 > .035

Zito weathered his previous gopher ball problem in 2002 because the defense was really good behind him and because he struck out a lot of batters. This year, he hasn't had good luck on defense, so he's felt it in his ERA. Similarly, Tim Hudson hasn't felt his drop-off in strikeouts because he somehow stopped giving up home runs on May 8. Anyways, all signs point to Hudson pitching worse next year, though improved defense and a rebound in strikeouts could offset the pain that will be caused by a return to his regular home run rate. In short, while we shouldn't expect a Cy Young out of Hudson or Zito in 2005, Mulder will probably continue doing what he's been doing all along.

Trivia Answer: Dave Hansen, Rocco Baldelli and Jacque Jones. Hardly the home run triumvirate.