Pettitte’s Fastballs

Andy Pettitte pitched a solid game last night, giving up just one run over 6.1 innings, and helping to send the Yankees to the World Series. Pettitte had a good, but not great, year. Actually, his peripherals were quite poor compared to his recent past. His walk rate was at its highest since 2000:

And his GB and FB numbers were the worst they have been in years:

On the other hand, his K/9 rate was in line with his recent past.

On a per pitch basis, the culprit for these changes seems to me to be his four-seam fastball (he throws a four-seam fastball, a two-seam fastball, a cut fastball, a changeup and curve). It went from being in the zone 53% of the time (pre-2009 pitchf/x era) to just 50% of the time this year. And the ground ball rate on it went from an amazing 49% (very good for a four-seam fastball) to just 36% this year.

Pettitte throws all three of his fastballs to both LHBs and RHBs (about 75% of his pitches to both RHBs and LHBs are fastballs), and the variation in their movement and location is a major weapon for him. I used the FanGraphs pitchf/x section color scheme to display their locations below: green for four-seam fastballs, dark blue for two-seam and light blue for cutters.


The two-seam is thrown to his arm-side (away to RHBs and in to LHBs) and the cut fastball down and to his glove-side (in to RHBs and away to LHBs), while his four-seam thrown in a larger area within the zone, but generally up and to his arm-side. This ability to throw all three fastballs to both RHBs and LHBs is a solid skill. His cutter is his best pitch by our valuations. It gets lots of out of zone swings and whiffs.

Even with the poor BB and GB peripherals his bottom line did not change much, as his numbers were buoyed by a BABIP and HR/FB both lower than his career averages. As a result, he provided solid value to the Yankees this year, 15 millions dollars worth. This past off-season saw him sign a 5.5 million dollar deal with which he was not entirely happy, but with bonuses it was worth $10 million. It will be interesting to see what Pettitte does this off-season. Even if his BABIP and HR/FB regress to career levels and his BB/9 and GB stay as poor as they were this year, he is still a good enough pitcher to provide a solid 10ish million dollars worth of value in 2010.