Last week I looked at different splits, and found some interesting things about Mariano Rivera's cutter and Takashi Saito's fastball. This week I'm going to continue looking at the splits and see what else I can find.

Rivera's cutter is ridiculously effective, especially against left-handed hitters. Nearly every single pitch he throws to a LHH is a cutter, yet they still swing and miss at the pitch. After writing about Rivera's cutter, I wondered if there were other pitchers who approached left-handed and right-handed hitters with only one specific pitch. Somewhat surprisingly, there were other pitchers who, perhaps unwittingly, were going after certain hitters with only one pitch. The table below shows these pitchers and how often they throw that pitch to LHH and RHH. The two columns labeled Freq. show the frequency that a particular pitch is thrown and Diff is just the Freq. LHH column subtracted from the Freq. RHH column.

Name              Pitch    Freq. to RHH    Freq. to LHH    Diff.
Mariano Rivera    FB       0.72            0.99           -0.28
Brian Fuentes     FB       0.70            0.99           -0.29
Trever Miller     FB       0.68            0.95           -0.27
Macay McBride     FB       0.87            0.95           -0.08
Kevin Cameron     FB       0.80            0.89           -0.09
Alan Embree       FB       0.89            0.72            0.17
Chris Young       FB       0.63            0.88           -0.26
Bartolo Colon     FB       0.67            0.85           -0.17
Jonathan Papelbon FB       0.85            0.74            0.10
David Riske       FB       0.85            0.81            0.04

All of the pitchers on the list would be considered fastball pitchers, but one thing to keep in mind when looking at the table is the different pitches each pitcher has and how that impacts pitch frequency. Macay McBride doesn't appear to have have a very extensive repertoire of pitches he feels comfortable with, so he throws mostly fastballs to both groups of batters. Every batter has a great chance of seeing a fastball from McBride, so there's really no secret about it. The more interesting cases are where batters from one side see a lot more fastballs than batters on the other side, like with Rivera, Fuentes, Miller, and Young. In these cases, knowing how the pitcher approaches different handed hitters is much more interesting and important than knowing how he approaches hitters overall.

In Brian Fuentes' case, the reason he throws so many more fastballs to LHH is because of his arm angle. He slings the ball from an arm slot between sidearm and three-quarters, which initially causes the ball to appear behind a LHH. If you check out Fuentes' career splits, the difference shows up there as well. Overall, LHH have hit him much worse than RHH, even though LHH should only be looking for fastballs.

I mentioned earlier that I thought it was interesting to look at cases where pitchers drastically altered their pitching style to different handed hitters, and the next step in examining those cases is to look at which pitches had the biggest differential.

Name            Pitch   FreqR   FreqL   Diff.
J.J. Putz       CT      0.71    0.27    0.43
J.C. Romero     FB      0.43    0.79   -0.36
Huston Street   SL      0.62    0.27    0.35
Joe Beimel      CT      0.76    0.42    0.34
Lance Cormier   CT      0.65    0.31    0.33
Justin Hampson  SL      0.30    0.61   -0.32
Kenny Rogers    CH      0.65    0.34    0.31
Edwin Jackson   SL      0.42    0.12    0.30
Todd Jones      FB      0.70    0.41    0.29
Brian Fuentes   FB      0.70    0.99   -0.29

These pitches all have different reasons for being thrown so much to hitters on one side. Putz's cutter/2-seam fastball gets a lot of swinging strikes when he throws it against both RHH and LHH, but his regular fastball and changeup aren't as effective against RHH as they are against LHH, which could be causing him to use more cutters at the expense of his changeup and 4-seamer vs. RHH. JC Romero's fastball is very hittable, but his arm angle is a slightly lower than normal, which lets him get away with frequently throwing the pitch to lefties. Even though both left-handed hitters and right-handed hitters posted identical SLGBIP and BABIP values on Romero's fastball(both of which count homers), when left-handed hitters swung at the pitch, they missed 26% of the time, while right-handed hitters swung and missed on only 6% of their swings.

Huston Street's slider also appears on this list. Street's slider is a great pitch against RHH, getting more swings and misses than an average slider (34% of swings against Street are misses vs. 24% overall) and when batters do put the ball in play, it is with far less authority than for an average slider (.296 SLGBIP vs. .502 SLGBIP). Street is pretty safe when he throws his slider to righties, because when they swing at it, there's a good chance they'll miss it and if they put it in play, there's a good chance it will turn into an out. That combination made me think about pitches that carried different amounts of risk for the pitcher throwing them, specifically pitches that not only posed a high risk (a high SLGBIP) but also had a high reward (high swing and miss percentage).

I created the list below by eyeballing my list of pitches and picking the ones that had both a high swing and miss rate and a high SLGBIP. The pitches are based on the handedness split, so for the line with Haren's changeup, you would read it as, against right-handed hitters, he threw a total of 819 pitches, 22% of which were changeups. When batters swung, they missed 47% of the time and when the ball was put in play, the slugging percentage was .652. For some perspective, the average amount of misses when the batter swings at a changeup or slider is 25% and the average SLGBIP for those pitches is right around .500.

Name              Pitch   Batter  Tot.  Freq    Sw%     SLGBIP
Dan Haren         CH      R       819   0.22    0.47    0.652
Chad Gaudin       SL      R       710   0.39    0.43    0.750
Jeremy Bonderman  SL      R       353   0.42    0.42    0.852
Rudy Seanez       SL      R       329   0.30    0.42    0.737
Shaun Marcum      SL      R       443   0.21    0.42    0.737
Jake Peavy        SL      R       820   0.21    0.41    0.630
Johan Santana     CH      R       456   0.34    0.41    0.897
Jonathan Broxton  SL      L       288   0.36    0.39    0.684

Wow, there are some good pitches and pitchers on that list. This is partly because half of the criteria to be included is to have a high swing and miss rate on a certain pitch. However, the other criteria is that the pitch is hit hard when it is put in play, so it's somewhat surprising that I have multiple Cy Young winners on the list. I'm not sure exactly what's going on, but the advantage of getting swings and misses must partially offset the high SLGBIP. Johan Santana'schangeup is the pitch whose appearance on the list surprised me most. His changeup is thought to be one of the best pitches in baseball, but when RHH put the ball in play, the SLG is on par with Bob Wickman's fastball to LHH. I'm almost as confused as I was last week when I found that lefties know Rivera's cutter is coming and still can't hit it.