Six years ago, Baseball America reported that Brandon McCarthy's best pitch was a two-seam fastball. This report, it seems, was in error. McCarthy told Baseball Time in Arlington, "I had tried dozens of times to throw one but really never had any success with it until this most recent attempt."
The most recent attempt actually started last summer. When he returned to the rotation in September, McCarthy was already experimenting with both a two-seam fastball and a cut fastball.
The Toronto Blue Jays got the first glimpse of McCarthy's new two-seamer on September 1st, 2009. In that game, McCarthy worked 6.1 innings and induced more ground outs than fly outs for just the second time all season, a 10-to-7 ratio.
Over his final six appearances, McCarthy used the two-seamer quite frequently but went to his cut fastball with less regularity (as far as I can tell from the PITCH f/x data).
In those games, McCarthy induced a 1.44 ground-to-fly ball ratio (52 ground ball outs, 36 fly ball outs). This was nearly twice his career rate of 0.82. On top of that, McCarthy allowed only two home runs over his final 33.1 innings, a rate of 0.54 home runs per nine innings. His career rate, including these six starts, is 1.33 home runs per nine innings.
The small sample size should be considered; however, even with some regression toward the mean, these improvements are jaw dropping.
McCarthy credits these improvements to the lower arm slot that is part of his mechanical overhaul, "Now I'm able to make the ball move more than I was able to previously. I had always been a strictly four-seam fastball guy, and that pitch, without plus velocity, can only take you so far.
"The cutter/sinker mix allows me to miss more barrels and induce a lot more groundouts. Last September my GB/FB rates were higher than I've ever had, and that was only while experimenting with the pitches."
The early results were very encouraging, and though he has struggled with command this spring, McCarthy is excited about his future with these two pitches in his arsenal.
"I feel like, employing them full time, I can become above average in terms of ground ball rates. The two pitches themselves are fun to gameplan with, so I'm excited each time out. They can only help my secondary offerings, and I think that my changeup can truly help both pitches become above average."
When asked about the future of his four-seam fastball, McCarthy responded, "For right now, I'm figuring, 'Why throw something straight, if I can make it move?'" That doesn't mean that the four-seamer is no more. McCarthy added, "Everything is an evolving process, so no book is ever closed."
With so many changes coming in such a short time, one wonders how comfortable McCarthy is with all of it. Other questions linger, as well, particularly the health question and the long-term viability of these changes.
"So far, so good. But this question isn't answered until next November. It's repeatable, and that, in turn, is allowing me to keep developing some new pitches. So, in that regard, it's been successful, but again, it's an evolving thing with no clear finish line."
[Additional reading: Retooling Brandon McCarthy: Part I]