Rivera’s Cutters Working the Count

We’re pleased to welcome Albert Lyu as the newest writer for FanGraphs. He impressed us with his submissions to the Community Blog, and so we’ve found a spot for him here on the team. We think you’ll enjoy having his work published here regularly.

Dave Allen has talked at length about Mariano Rivera’s cutters and how well he locates them, but it’s always interesting to analyze what many consider to be the greatest pitch in the game. I don’t believe that there is any other pitch in the game right now that can be used so exclusively yet so dominantly the way that Rivera uses his cutter.

We know that Rivera has pinpoint control and likes to work the outer and inner edges of the strikezone against both right-handed batters and left-handed batters. We also know that Rivera is great at working the count, rarely getting to three balls. Combining both of these ideas, can we figure out how Rivera works the count based on the locations of his cutters?

I took all of Rivera’s cutters since 2007 and split them into different count situations not including the 3-2 count: first pitch, behind in the count, ahead in the count, and with two strikes. Borrowing Dave’s terminology, I wanted to see if Rivera’s cutters exhibit a bimodal distribution consistently and how the pitches are distributed differently around the inside and outside edges of the strike zone based on the count situation. First up, let’s compare the first pitch of an at-bat Rivera throws against right-handed hitters to left-handed hitters (all plots are from the catcher’s perspective):

Keep in mind that Rivera’s cutter moves toward LHH and away from RHH. It’s clear that Rivera likes to start off an at-bat by throwing his cutter in the same location, throwing outside to RHH consistently but occasionally going inside as well. Against LHH, Rivera almost exclusively throws inside on the very first pitch. Notice also that most of these pitches are within the strikezone, again, mostly outside to RHH and inside to LHH. Let’s take a look at how Rivera locates his cutter when he is behind in the count with more balls than strikes:

In this case, Rivera forms more of a horizontal bimodal distribution than on the first pitch, locating cutters on the inside and outside edges of the strikezone against both handed batters. He also consistently hits the strikezone, but isn’t afraid to go inside on LHH and out of the zone even when he’s behind in the count. Let’s compare this with his cutters when he’s ahead in the count with more strikes than balls:

Here, we see a very clear bimodal distribution, where Rivera works both the inside and outside edges to both RHH and LHH. Against RHH, he loves to go outside again, but goes inside a lot more than he does on the first pitch. Against LHH, he goes inside more, but also goes outside a decent amount. What amazes me about this specific graphic is that the middles of each of the four hot spots of Rivera’s cutter locations are bisected by the border of the strikezone, whether it’s the inside border or the outside border. This speaks to the uncanny control that Rivera has and how he loves to attack either edge of the strikezone when he’s ahead in the count, likely inducing both called strikes and swinging strikes. Finally, let’s look at Rivera’s cutter locations when he has two strikes:

These look similar to the plots when Rivera is ahead in the count except for two significant differences. Against RHH, Rivera goes higher in the zone, especially up and inside in addition to the outside edge. Against LHH, Rivera goes outside much more than he goes inside, very different from the other count situations against LHH where Rivera goes inside more. With two strikes, both RHH and LHH should expect the outside cutter most of the time.

Just looking at traditional statistics will appropriately show how dominant Rivera has been in his career (2.21 ERA, 8.2 K/9, and 1.00 WHIP in over 1145 IP). However, the plots above tell us how he has achieved such success: by living on the black against both right-handed and left-handed hitters and being able to consistently hit his various spots so that hitters are forced to swing at difficult pitches no matter the count.