Johan Santana is Not Perfect

At the beginning of the year (probably around June 9^th), there were a bunch of “What’s Wrong With Johan” articles, because Santana had started the season 6-6. This, of course, was dumb, because he had a 3.24 ERA, and had struck out 96 in 86 innings- there was very little wrong with Johan, beyond the fact that the Twins had scored three or less runs in 9 of his 13 starts.

Predictably, Santana has improved since, and now stands at 14-9 with a 2.97 ERA. However, there is a disturbing trend that had been true throughout the year.

Here is Santana’s ERA (in red), and his FIP (Fielding Independent ERA, based soley on K/9, BB/9, and HR/9 (in blue), for each year since ’04.

The disturbing thing about this year’s performance has been the spike in FIP. The reason for the increase is quite obvious.

Well, that’s bad. He’s gone from giving up 0.91 HR/9 over the last three years to 1.34 HR/9 this year, which is the only reason his FIP has increased so drastically (his BB/9 and K/9 are both up slightly).

This is happening because Santana is inducing way more fly balls. From ’04-06, his FB% was 42.0%; this year, it’s 45.4%.

But that’s not all. FanGraphs also keeps track of Infield Fly Balls (or popups), which pretty consistently don’t end up over the fence. Despite his increased fly ball tendency, Santana actually has allowed less IFFBs this year.

The “Actual FB” statistic is simply fly balls minus infield fly balls. To my knowledge, the increase in HR/Act. FB is bad luck, while the increase in actual FB% is Santana’s fault.

From here on out, assuming he reverts to his previous HR/Act. FB rate, we would expect him to give up (on average) 5.5 HRs over his last seven starts (a rate of 1.04 HR/9). Coupled with his current strikeout and walk rates, that means an expected ERA of 3.26.

Picture taken from USA Today. One graph I took from FanGraphs, the other I made with FanGraphs data. Stats taken from FanGraphs and Baseball Reference.