The Mariners story of the day in the Seattle-area Sunday papers is Jarrod Washburn's goal of improving against left-handed hitters this season. Last year he allowed career highs of .317 AVG against and .875 OPS against.
Washburn's theory, quoted in each of the papers, as to why he sucked against lefties last year:
"I used to throw inside to lefties all the time. For some reason — and I don't know what it was — I got away from that last year."
Sounds good, but it's not true. Here's his percentage of inside pitches to lefties since 2002, according to Stats Inc. (the data dated to only 2002).
2006: 84 inside pitches of 586 total pitches to LH -- 14.3%
2005: 79 of 533 -- 14.8%
2004: 72 of 590 -- 12.2%
2003: 159 of 704 -- 22.5%
2002: 190 of 684 -- 27.7%
And his AVG and OPS against vs. LH:
It's not the sheer number of inside pitches that is impacting his fate. He did used to throw inside more, but the frequency started ebbing in 2004, not last year. And there doesn't necessarily seem to be a correlation between the number of inside pitches and success (see 2003 vs. 2004).
This doesn't identify why he was so bad against lefties last year, just that the reason likely isn't what Washburn thinks it is -- which is a problem in and of itself.