The Most Important Play of Game One

Neither the Red Sox’ four-run margin of victory, nor the ease with which Craig Kimbrel finished off the ninth, really do justice to the intensity of Game One of the World Series. Despite the final score, only 10 of the game’s 80 plays took place with a run differential greater than two runs. There were 11 high-leverage plays overall, and the average leverage index was 1.14, which is higher than normal. It was a game with important, exciting moments — and none were more important than certain moments of the seventh inning.

In terms purely of win expectancy, Eduardo Nunez’s three-run homer in the bottom of the seventh off Alex Wood was the game’s top play. When Nunez stepped to the plate with runners on first and second, two outs, and a one-run lead, the Red Sox’ chances of winning the game were 77% — which is to say, good but far from from certain. After his three-run homer — which came off the bat with a launch angle just under 20 degrees but managed to clear the Green Monster, anyway — Boston’s win probability increased to 96%. The game was pretty much over.

If that ball were directed a little more toward center, it doesn’t make it out of the park. If the launch angle were even a tiny bit lower, it would have just bounced off the wall. Since the beginning of 2015, there have been something like 350 homers over the Green Monster (launch direction -12 or less). Of those homers only eight have had a launch angle below 20 degrees, including a shot by Hanley Ramirez this past April and Alex Rodriguez’s 660th homer back on May 1, 2015. Of those eight homers, five were no-doubters traveling over 415 feet. At 373 feet, Nunez’s blast had the shortest distance traveled, making it the wall-scrapingest homer of the last four seasons.

While, as I said above, Nunez’s homer was the biggest play of the game in terms of win expectancy, it actually wasn’t the most important — or maybe most consequential — play of the game. That actually occurred in the top half of the seventh inning, when Manny Machado came to the plate. If you just look at the Win Expectancy Chart, the Machado appearance might not be that noticeable.

However, if you look at the bottom of the chart, where Leverage Index is visible, Machado’s plate appearances becomes more noticeable.

Ultimately, Machado drove in a run with a sacrifice fly, cutting the Red Sox lead down to one run. Yet the win expectancy for the Red Sox actually went up as a result, from 64.5% to 69.7%. For the Red Sox, the out was more important than the run. Our Play Log indicates that, when Machado stepped to the plate with the bases loaded and one out, the run expectancy for the situation was 1.64. In other words, an average team would score 1.64 runs in that situation. Machado got one run home, but with two outs and runners on first and second, the run expectancy dropped to just 0.47 for the Dodgers. Even adding in the run already scored, 1.47 actual plus expected runs is less than the 1.64 expected runs with which the plate appearance began, so Machado’s sac fly actually made things worse than expected and gave the Red Sox a better chance to win the game.

To explain this further in terms of win expectancy, let’s run through some Machado scenarios and see the change in win expectancy from the 64.5% when Machado stepped up. Using our WPA inquirer, we can see how the game could have changed depending on the outcome of the plate appearance.

Potential Manny Machado Outcomes in the Seventh
Outcome Red Sox WE Before Red Sox WE After Change
Double Play 64.5% 88.1% 23.6%
Strikeout 64.5% 76.1% 11.6%
Force at Home 64.5% 76.1% 11.6%
Sac Fly 64.5% 69.8% 5.3%
Groundout RBI 64.5% 66.4% 1.9%
Walk 64.5% 50.5% -14.0%
Single, 1 RBI 64.5% 50.5% -14.0%
Single, 2 RBI, 12_ 64.5% 44.1% -20.4%
Single, 2 RBI, 1_3 64.5% 38.9% -25.6%
Double, 2 RBI 64.5% 35.7% -29.6%
Double, 3 RBI 64.5% 29.6% -34.9%
Home Run 64.5% 21.3% -43.2%

This table should help illustrate why Machado’s plate appearance was so important. Basically any play that ended in an out was going to improve the Red Sox’ chances of winning the game. On the other hand, Machado could have changed the win expectancy anywhere from an 88% chance for the Red Sox to a 79% chance for the Dodgers with just one swing. Leverage Index measures how critical a plate appearances is towards determining the potential outcome of the game.

For reference, compare Machado’s plate appearance to the Nunez home run in the bottom half of the inning. The best case for the Red Sox in that latter case was the homer itself — which facilitated a 19-percentage-point increase in win expectancy. If Nunez made an out to end the inning with a one-run lead, Boston’s win expectancy would have dropped by only four percentage points. That potential spread is nowhere near Machado’s plate appearance, making the out that Ryan Brasier got more important than Nunez’s home run given all the potential negative possibilities for the Red Sox.

As for the out by Brasier, he got himself into trouble by loading the bases, but made a near-perfect pitch to Machado to induce the sacrifice fly.

A 96 mph four-seam fastball on the outer edge of the plate to Machado to open the at-bat induced a very good outcome for Brasier. I looked at all four-seam fastballs at least 95 mph in that zone (Detailed Zone 16 at Baseball Savant) to righties from righties, and looked at the outcomes this season. Of the 3,681 pitches in the sample, just seven were hit for homers. The pitch is called a strike two-thirds of the time when it is taken, and as many balls are put in play as whiffed.

Pitches Like Brasier’s to Machado in the Seventh
Outcome Frequency
Called Ball 17.3%
Called Strike 33.4%
Swings 49.1%
Whiffs 13.0%
Batted Ball 13.7%
HR/Batted Balls 1.4%
XBH/Batted Balls 7.9%
wOBA .210
SOURCE: Baseball Savant
95+ Fourseam Fastball on outer edge of the plate thrown by a righty to a righty

This season, Machado saw 31 pitches like the one Brasier threw him. He took 12 of those pitches, with half going for strikes. Of the 19 swings, though, he put the ball in play just three times, leading to two easy fly balls and one single. This isn’t to say that those results against Machado are meaningful, but that they do line up with typical behavior on that type of pitch. Brasier got himself and the Red Sox in trouble, but thanks to one really good pitch, he was able to retire Machado at the most critical juncture of the game.





Craig Edwards can be found on twitter @craigjedwards.

30 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Josermember
5 years ago

This is a lovely discussion of WE and LI using a vivid and concrete example. I’m passing it along to my baseball buddies who need a little coaxing to get on the analytics train.

Garyth
5 years ago
Reply to  Joser

Exactly what I did halfway through the article!

Roger McDowell Hot Foot
5 years ago
Reply to  Joser

Particularly good as an illustration of the principle that the moments when it looks like something big happened aren’t always the biggest moments. (This is a cognitive bias that all of us have to some degree, traditionalist or stat-head, so it’s nice to have a solid empirical reminder either way.) Sometimes the run-prevention side of baseball gets short shrift like this, because when it’s working right, it can look like, well, preventing things from being done by the other side, rather than like doing something big and important yourself.