Contreras’s Second Arm Slot Redux

In an injury-depleted Phillies bullpen Jose Contreras‘s surprising performance has been a huge help. He has pitched 14 innings and allowed just one run (on a solo home run) while striking out 20 and walking two. That performance has earned him some save opportunities while Brad Lidge and Ryan Madson are on the DL.

Last September I noted that Jose Contreras had stopped using two different arm slots in mid-August of 2009. In light of Contreras’s recent performance I was curious to see whether he was still going with the one arm angle or had gone back to two.

As I did with Brett Anderson, here I plotted small histograms for each of Contreras’s appearances going back to the beginning of 2009. The x-axis is the horizontal release position in feet (0 is the middle of the rubber) and I separate the data by batter handedness.

Here the difference in horizontal release position is not from shifting on the rubber, but from different arm slots. When pitching to lefties he throw with a standard delivery, so he releases the ball closer to the center of the rubber. To RHBs he, sometimes, uses a lower arm angle so he releases the ball closer to 3B (further from the middle of the rubber). In mid-August of 2009 he gave up the lower arm angle and started pitching to both RHBs and LHBs from the standard slot.

But since the start of 2010 he has recovered the lower arm slot. It also looks like his release point is more consistent, but I think this is because he has fewer pitches per appearance now, as a reliever, than he did in early 2009, as a starter. But I could be wrong.

Contreras’s excellent performance cannot be fully attributed to his re-adoption of the lower arm slot — luck has played a huge role. But I would bet that it doesn’t hurt. It is harder for RHBs to pick up pitches coming from that lower arm slot, so if Contreras can effectively pitch from there it should be a help against them compared to the couple months last year when he was pitching just from the one arm slot.

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Dave Allen‘s other baseball work can be found at Baseball Analysts.

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Pitching in relief has also allowed him to add 2 mph to his fastball, which always helps.