Rivera's Cutters Working the Count

I've talked about Mariano Rivera and his cutter in the past, but it's always interesting to analyze what I 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 3 balls in a count. Combining both of these ideas, can we figure out how Rivera works the count based on the locations of his cutters?

To do this, let's first look at Rivera's cutters by each count since 2007:

0-0: 218 to RHH, 343 to LHH
0-1: 105 to RHH, 188 to LHH
0-2: 57 to RHH, 42 to LHH
1-0: 80 to RHH, 101 to LHH
1-1: 86 to RHH, 108 to LHH
1-2: 60 to RHH, 55 to LHH
2-0: 24 to RHH, 28 to LHH
2-1: 41 to RHH, 37 to LHH
2-2: 47 to RHH, 53 to LHH
3-0: 2 to RHH, 4 to LHH
3-1: 4 to RHH, 4 to LHH
3-2: 15 to RHH, 19 to LHH

Note that these are cutters used in different pitch counts, not total pitches. Rivera does occasionally use two-seam and four-seam fastballs, and he has used traditional fastballs 16.2% of the time this season so far. However, a quick glance at the above list shows us that Rivera rarely falls behind in the count, or rarely uses his cutter when he has three balls. To analyze how Rivera works the strikezone based on the count, it wouldn't be sensible to do a 12-count plot of Rivera's cutters, as he's only thrown the cutter twice to RHH on 3-0 counts since 2007. Instead, let's combine the counts to different situations to see how Rivera locates his cutters as a result:

Count Situation (Not including full count)
On first pitch: 218 to RHH, 343 to LHH
Behind in the count: 151 to RHH, 174 to LHH
Ahead in the count: 222 to RHH, 285 to LHH
With two strikes: 164 to RHH, 150 to LHH

These sample sizes are much better for our plots and should allow us to accurately see how Rivera's cutters are located in different count situations. Let's take a first crack at Rivera's cutters against right-handed hitters on the first pitch and behind in the count along with the batter's swing zones and contact zones:



On Rivera's first pitch of the at-bat, he likes to throw a strike right away, hitting the outer edge of the zone against right-handed hitters, sometimes outside the zone. Hitters have a low contact rate on the first pitch, and when they do, they are better at making contact when Rivera's cutter is up in the zone. When Rivera is behind in the count, he still likes to get the outside edge of the strikezone, but this time looks to throw a pitch in the zone most of the time. Here, hitters make more contact off of where Rivera tends to throw, where the 50% swing and contact zones both encompass Rivera's hotspot. Note that there are shades of yellow on the inner parts of the zone as well, showing that Rivera does throw inside occasionally when he's behind in the count.

Let's look at the same count situations against left-handed hitters instead:



The first pitch to left-handed hitters is approximately the same location as against right-handed hitters, except Rivera locates up and inside in addition to middle inside. LHH have a much smaller swing zone on the first pitch compared to RHH. However, when they do swing, it is usually where Rivera locates his cutter most frequently. This is to say that Rivera's first pitch to LHH is likely to get swung at if it's placed in his hotspot. LHH also have a larger contact zone than RHH and it's located right in that hotspot, which means LHH make contact on the first pitch more often than RHH. Looking at cutters behind in the count to LHH, Rivera still likes that right edge, but locates to the left (outer edge for LHH) more often than to RHH (inner edge). He also goes inside and out of the zone on LHH in this situation more than he does going outside out of the zone to RHH.

What about his cutters to right-handed hitters ahead in the count and with two strikes? Let's take a look:



Here, Rivera goes outside the zone to RHH more often when he has the upper hand. He also locates inside to RHH sometimes too, but the epicenters of his main hotspot shifts to the right outside the zone when he's ahead in the count or with two strikes compared to when he's behind the count. It also seems as if batters swing more freely, swing zones that encompass much of the strikezone and outside as well.

Let's see if Rivera works left-handed hitters when he's ahead in the count the same way he works right-handed hitters:



Here's something different. Just as Rivera throws his cutters outside to LHH more often than inside to RHH when behind in the count, here we can see hotspots emerging on the left outer edge to LHH. When he's ahead in the count, Rivera works either edge, but goes inside and out of the zone quite often (Rivera's cutter moves in on LHH and away from RHH). On two strikes, it's pretty much anyone's guess whether Rivera wants to come outside and then barely hit the outer zone, or come into the zone and just hit the inside of the zone. The best bet for left-handers is to expect the outside cutter, as this count situation yields cutters in this location more than in other situations. Looking at the swing zones, LHH are pretty much swinging anywhere Rivera throws his cutter.

Finally, let's look at a table of different pitch outcomes and batter reactions based on the count situations we looked at above:



These are percentages of total pitches in those count situations, except for Whiff%. The distinction between SwStr% and Whiff% is that SwStr% is a % of total pitches while Whiff% is a % of total pitches swung at.

On the first pitch, RHH and LHH both swing less than 40% of the time, but LHH are definitely more successful at making contact and putting the ball in play. RHH whiff more in most count situations, but Rivera is able to get LHH to whiff more than RHH on two strikes. RHH put the ball in play 40% of the time when Rivera is behind in the count, but only 28.4% when ahead in the count. LHH put the ball in play about 35% of the time whether or not they are behind or ahead in the count.

To recap(itulate), it would appear that RHH are especially vulnerable on the first pitch, whiffing 28% of the time when they swing. RHH would hope to be behind in the count and expect a cutter inside the zone for their best chance of putting the ball in play. Otherwise, Rivera will paint the outer edge if he is ahead, pitching to the black, a difficult pitch to hit to say the least. For LHH, who make more contact off the right-handed Rivera than RHH, Rivera counters by working both edges of the zone. LHH still get whiff rates as high as 19.4%, and especially don't want to let Rivera get ahead in the count, as he will work either the outside edge or the inside edge.

Just looking at traditional statistics will appropriately show how dominant Rivera has been in his career, with a 2.21 ERA, 1.00 WHIP, .209 opponent's BA, and 1044 strikeouts in 1137+ innings. The plots and analysis above shows 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 he gets hitters to swing at difficult pitches no matter the count.