Santana’s Recent HR Drought

The biggest move this offseason saw Johan Santana heading to the Mets in exchange for Carlos Gomez and some more prospects. The former two-time (should be three-time) Cy Young Award winner looked to solidify a pitching rotation that seemed more than capable of making fans forget all about last year’s end of season breakdown. Coming off of a relative down year—a down year for him was still better than the up year of most others—there were some who questioned whether or not Johan would be able to regain whatever made him successful pre-2007.

One of the biggest reasons his performance suffered last year came in the form of home run balls. From 2003-2006 his HR/9 ranged from 0.85-0.97; in 2007 it jumped to 1.36 as he allowed 33 dingers. I recently took a look at his Pitch F/X data over the last year and a half to see if he had done anything differently on hits as compared to fouls or swinging strikes. The results also showed that his home run balls—or other hard hit balls—generally came from pitches not just with lesser velocity and/or movement but also very poor location: Most of his home run balls came on pitches right down the middle.

In Johan’s first 60 innings this season he surrendered 11 HR; over his last 34.2 he has surrendered just one.

First 9: 60.0 IP, 52 H, 11 HR, 15 BB, 57 K
Last 5: 34.2 IP, 36 H, 1 HR, 9 BB, 29 K

Of course it is too small of a sample to generate definitive conclusions but we can still investigate and make observations pertaining to whether or not any discrepancies in relevant Pitch F/X data exist in this split. For starters, here are the velocity and movement data for his first nine starts:

FA: 90.54 mph, 5.63 horiz/9.22 vert
SL: 84.18 mph, -0.98 horiz/4.53 vert
CH: 79.69 mph, 5.51 horiz/8.13 vert

And here is the same data in his last five starts:

FA: 92.39 mph, 6.68 horiz/9.64 vert
SL: 84.89 mph, -0.57 horiz/4.64 vert
CH: 79.94 mph, 6.48 horiz/7.54 vert

He has thrown harder and with more movement lately. One of the problems with his hard hit balls, as mentioned above, dealt with the percentage of pitches he threw down the middle. Here are his splits of pitches thrown down the middle:

First 9: 11.5%
Last 5: 11.9%

Though it appears he has thrown slightly more down the middle recently the small sample detracts from any real discrepancy. How about his accuracy? Here is his Ball/Strike/In Play breakdown for the first nine starts, followed by the last five:

K: 46.8%, 45.1%
B: 35.1%, 34.5%
X: 18.1%, 20.4%

Speaking of balls put in play, have any less fallen in for hits lately?

Outs In Play: 67.5%, 64.2%
Hits In Play: 32.5%, 35.8%

Despite sustaining a similar level of accuracy and balls put in play he has actually allowed a slightly higher percentage of those in play to fall in for hits. Looking at his WHIP in these two different spans (1.12 compared to 1.25) it seems that he was hit less in the early going though those hits were of a higher value than recently, despite the increase in hits given up lately. Lastly, has he gotten ahead of hitters any more or less lately? Here is his first-pitch strike split:

First 9: 51.2%
Last 5: 44.8%

All told, not much can truly be garnered in terms of data discrepancies but Johan has gotten ahead of hitters less as of late, has essentially sustained his patterns of accuracy, is throwing virtually the same percentage of pitches down the middle, and is allowing more hits. All of these signs would intuitively point toward similar or worse performance and yet he has thrown better lately. Perhaps his increase in velocity and movement over his last five starts has prevented hitters from getting the fat part of the bat on the ball quite as often. Definitely something to look out for as the season progresses.