Mike Petriello

Statcast of the Day: What a relief!

Three of five batted balls hit off Chapman had .000 expected average

Statcast of the Day: What a relief!

CHICAGO -- In a postseason that's rapidly redefining how we think about modern relievers, Aroldis Chapman couldn't let Andrew Miller and Kenley Jansen have all the fun. Chapman pitched a career-high 2 2/3 scoreless innings on Sunday night as the Cubs topped the Indians, 3-2, in Game 5 to send the series back to Ohio, and he also set a postseason record (since data was first kept in 2008) for most pitches in a game over 100 mph with 19.

You know the Chapman story by now, or you ought to. He throws insanely hard (by himself, he owns 40.8 percent of all Major League pitches tracked at 100 mph or above), and he racks up record-setting strikeout totals. Chapman did both of those things in Game 5. But he also showed off the other thing that makes velocity so dangerous -- when he did allow hitters to make contact, it was almost always bad contact.

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Think about it from the hitter's perspective. We've known for a while that when a hitter makes contact, two important things have to happen to ensure success. First, obviously, you need to hit it hard; the Major League average on balls hit 100 mph or harder this year was .629. And secondly, you need to hit it at the right launch angle, because if you hit it straight up or pound it into the ground, then it doesn't really matter how hard you hit it -- it won't be a hit.

Game Date Matchup Highlights
Gm 1 Oct. 25 CLE 6, CHC 0 video
Gm 2 Oct. 26 CHC 5, CLE 1 video
Gm 3 Oct. 28 CLE 1, CHC 0 video
Gm 4 Oct. 29 CLE 7, CHC 2 video
Gm 5 Oct. 30 CHC 3, CLE 2 video
Gm 6 Nov. 1 CHC 9, CLE 3 video
Gm 7 Nov. 2 CHC 8 CLE, 7 (10) video

Roughly speaking, the ideal angle for a line drive is around 12 degrees, and for a home run, where you want more elevation, it's about 28 degrees. Batted balls hit between 10 degrees and 40 degrees this year, regardless of exit velocity, had a .523 average.

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Got it? Hitting the ball hard is good; hitting the ball at the right angle is also good. Now you know a bit about exit velocity and launch angle, and now we can share what makes Chapman's Game 5 outing so interesting. He allowed five batted balls, ranging in exit velocity from 64 mph (Mike Napoli's groundout) to 105.8 mph (Roberto Perez's groundout), but look at their launch angles and expected average:

Perez groundout: -5 degrees, .395
Rajai Davis single: 0 degrees, .229
Jason Kipnis flyout: 51 degrees, .000
Napoli groundout: -13 degrees, .000
Carlos Santana flyout: 48 degrees, .000

Two of those balls were at a zero-degree launch angle or lower, which means that they were grounders. (Major League average on balls hit at 0 degrees or lower: .185). Two were hit at 48 degrees or higher, which means they were popups. (Major League average on balls 48 degrees or higher: .022.) Those are extremely low-probability batted balls, and while Davis did manage to get a single, that was more of a mental error on Chapman for failing to cover first for a potential throw from Anthony Rizzo, who'd made a fine play near the line.

Davis' infield single in the 8th

You'll also notice that the last three batted balls that Chapman allowed -- two popups and a grounder -- all had an expected average of .000. What that means is that for three straight balls in play, the combination of exit velocity and launch angle never led to a hit this season. In fact, let's actually have some fun and expand that out, to show the final five Cleveland hitters who stepped to the plate, with their expected average.

Kipnis flyout: .000
Francisco Lindor strikeout: .000
Napoli groundout: .000
Santana flyout: .000
Jose Ramirez strikeout: .000

Chapman's eight-out save

That's a lot of zeros. It goes without saying that strikeouts never lead to a hit, and that's why pitchers love to chase them so much. But that's not the only way you can guarantee that the opposing batter isn't going to do damage. If you can get the hitter to make contact at certain angles and certain exit velocities, the outcome can be nearly as guaranteed. Chapman is a strikeout legend, of course. On Sunday night, he was a contact king.

Mike Petriello is an analyst for and the host of the Statcast podcast. He has previously written for ESPN Insider and FanGraphs. This story was not subject to the approval of Major League Baseball or its clubs.