Sidearm Pitchers with Reverse Splits this year???

As a right-handed submarine pitcher, you hear countless times that you will be more effective against righties and will struggle against left-handed hitters.  The past data agrees with this, as do most (if not all) coaches and past players.  So why are submarine/sidearm pitchers having more success against opposite handed hitters than same-sided hitters this year?  

I used data from the 7 pitchers who release the baseball at 3.5 feet and lower.  These pitchers (in lowest release to highest) are: Tyler Rogers, Adam Cimber, Ben Rowen, Eric Yardley, Joe Smith, Tim Hill, Aaron Northcraft.

Looking at the total of the 7 pitchers, they have better stats against in every category vs. opposing hitters of the opposite side they throw from.  This means right hand pitchers vs. left-handed hitters and lefty-hand pitchers vs. right handed hitters.  In the past, people have always said that hitters from the opposite side see the ball better, especially against sidearm pitchers.  If this is the case though, then why does the data tell another story?

Looking at the individual pitchers, 5 of 7 pitchers have a lower batting average against, on base percentage against, slugging against, and wOBA for opposite handed batters than batters from their same side.

To see what has been working for these pitchers and what has not been, I compared a pitcher who is doing very well (Tyler Rogers) and a pitcher who has struggled (Ben Rowen).  Tyler Rogers has reverse splits this year as well as for his whole career, while Ben Rowen has expected splits this year and throughout his career.  Both these pitchers have similar pitches, which helps the comparison.

They both throw a Sinker and a Slider with Rogers throwing 62% Sinkers vs. 32% Sliders, and Rowen throws 48% Sinkers vs. 52% Sliders. Looking at their sinkers, the only significant difference is their spin direction, and even that is only off from 4:00 to 5:00. Looking at sliders, the only significant difference is that Ben Rowen has a spin rate of about 350 RPMs higher. Due to this we would expect even more movement from him than we see in the devastating slider that Tyler Rogers has shown us.

The above splits show us that the pitchers are relatively similar against righties with Ben Rowen having the edge. What sets them apart is their numbers against lefties. There is such a huge difference in their success against lefties that has left one of them (Tyler Rogers) to have one of the best ERAs in the MLB, and the other pitcher (Ben Rowen) to be sent down to the minors.

It is no secret that these pitchers are attacking hitters on the outside part of the plate.  This next chart shows how consistent they each are at throwing on the outside part.

Notice that for the comparisons vs. righties, it is almost identical in the percentage of their pitches thrown to glove side vs. arm side. For lefties though, there is a big difference in how effective they are throwing their pitches to arm side. The biggest difference is sliders vs. lefties, as Rogers has located about 15% more on the arm side of the plate. For sinkers against righties though, Rowen actually has been more effective in getting them to his arm side, but has thrown 15% less strikes on those pitches than Rogers.

Looking vertically at where each of these pitchers throw, the sinkers are thrown at similar percentage for each height, but the sliders are very different. For sliders against righties, each of them have success in very different ways. Rogers targets the top of the zone, while Rowen targets the bottom of the zone. Looking at opponent batting average the edge goes to Rowen. However, the biggest difference in opponent batting average is on sliders vs. lefties. Rogers throws 18% more in the top of the zone and throws 8% less of them right down the middle of the plate. No lefty has gotten a hit against Rogers’ slider compared to the .308 batting average they have against Rowen. The key for all these sidearm pitchers against opposite-handed hitters is their slider/curveball.

The top 4 pitchers in this chart have reverse splits (do better against opposite handed batters).  These pitchers are having tremendous success on their sliders as shown in the chart.  If you are not familiar with dERA, it is a way of calculating a pitchers’ deserved ERA.  You may notice some numbers are negative, and that just means the pitchers have done so well during the small sample of pitches that the model doesn’t even fit them yet. 

The bottom two pitchers on the chart highlighted in red are the pitchers with traditional splits who are struggling against opposite handed hitters.  Although their success on sinkers does not have much difference from the top 4, there is a clear drop-off when it comes to their sliders.

A well located and timed slider seems to be the equalizer for these sidearm pitchers. They have been able to become even more effective against opposite handed pitchers than their same handed hitters that they use to be specialist for. It will be interesting if guys like Ben Rowen and Eric Yardley can learn from the other pitchers’ data and focus on location to create a weapon to improve their numbers against lefties.

3 thoughts on “Sidearm Pitchers with Reverse Splits this year???

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  1. The lack of success vs same side hitters may be due to the quality of this hitters. Is it possible that only the best same side hitters face these guys and b the avg same side guys are PH for?

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