Santana’s Fastballs the First Time Through the Order by Dave Allen May 4, 2010 Yesterday I read an interesting piece in the New York Daily News (via Hardball Talk) about Mets’ pitching coach Dan Warthen’s plan for Johan Santana this season. Some worry that the declining velocity on Santana’s fastballs could negatively impact his devastating changeup. So Warthen wanted Santana to throw more fastballs, and particularly inside fastballs, the first time through the lineup so that his changeup is more effective in subsequent passes through the lineup. Setting aside the question of why you would want to announce Santana’s plan to the media I was interested to see whether Santana is pitching this way. Here is a look at Santana’s pitch breakdown (with percentage of fastballs that are inside indicated) broken up by first time through the order versus subsequent at-bats for before 2010 and in 2010. pre-2010 FA (%inside) CH SL first time 61.5 (10.4) 27.4 11.1 after that 59.0 (13.9) 30.0 11.0 2010 FA (%inside) CH SL first time 64.2 (12.1) 26.9 8.9 after that 56.5 ( 6.4) 28.4 15.1 It does look like Santana is throwing more fastballs the first time through the lineup compared to before and then fewer in subsequent at-bats. The inside fastball percentage also shows a trend in the direction indicated, although I don’t know how much of that is just noise. But instead of the reduced fastballs giving rise to more changeups in subsequent turns through the lineup it looks to me like it is giving rise to more sliders. At this point in the season I do not think we can attribute this change in usage to how he is performing, but it is interesting to note that the numbers bear out Warthen’s stated plan for Santana. More generally the question of whether additional fastballs the first time through the order make off-speed pitches more effective the next time through is an interesting one, but — as with all issues of pitch sequencing — it is a pretty daunting question to address.