All That Ned Yost Bunting Has Helped the Royals

Relative to the rest of the league, Ned Yost’s bunting isn’t exactly out of control. However, he does seem rather fond of the strategy, so he pulls it out pretty often, and it’s a big part of how he’s labeled online. The Royals bunted and ran like crazy people in the wild-card playoff against Oakland, and in Wednesday’s Game 4 against the Orioles, Lorenzo Cain sac bunted in the first inning, with nobody out, as the third hitter in the Kansas City lineup, facing Miguel Gonzalez. The Royals did score twice in the inning, but it was taken to be another bit of good Royals luck, and the bunt predictably drew its critics. If nothing else, it looked weird. Cain, again, was batted third, by his own manager.

But there’s a funny thing about Ned Yost’s sacrifice bunts. This goes beyond just the wild-card playoff bunts mostly being defensible. In theory, a sacrifice bunt is either successful or unsuccessful. Even if successful, it trades an out for a base or two. But bunts, as you know, have a whole range of potential outcomes. The Giants, just Tuesday, won on a walk-off sac bunt attempt. 2014 Ned Yost has called for a bunch of sacrifice bunt attempts, and overall, they’ve actually been good for the team.

This is all about Win Probability Added, or WPA. When you start learning about baseball analysis you’re exposed to run-expectancy matrices, and those provide the simplest possible argument against the sac bunt, but that doesn’t tell you enough. Teams don’t play baseball games trying to get runs. They’re trying to win. Because winning is always the goal, WPA should be the preferred metric, and while win expectancy and run expectancy will be very strongly linked, they diverge in precisely the sorts of situations where a sacrifice bunt might be reasonable. Also, there’s just more to the story. Because of the other possible bunt outcomes. I’m tripping over my own words, so let’s proceed toward some numbers.

This all started because I was thinking about the Giants’ walk-off bunt from Tuesday. That got me thinking about the Nationals’ two-run bunt against the Giants earlier, and then when you’re a baseball writer on the Internet, when you think about bunts, you eventually think about Ned Yost. The Baseball-Reference Play Index is awesome, and within its searchable Event Finder, it includes sacrifice bunt attempts. So I decided to look at all such attempts on a team level from 2014, and I took the additional step of leaving out pitcher bunts because many pitcher bunts are perfectly reasonable. People generally don’t get mad when a pitcher drops one down. People get mad when Lorenzo Cain drops one down. So now look at the resulting table, of 2014 data. You see all 30 teams, and you see the cumulative sac-bunt-attempt WPA. Surprise!

Team	Sac Bunt WPA
Royals	1.0
Blue Jays	0.7
Angels	0.5
Astros	0.5
Athletics	0.5
Nationals	0.5
Giants	0.4
Mariners	0.3
Brewers	0.2
Tigers	0.2
Mets	0.1
Yankees	0.1
Diamondbacks	0.0
Indians	0.0
Marlins	0.0
Orioles	0.0
Pirates	0.0
White Sox	0.0
Red Sox	-0.1
Dodgers	-0.2
Rockies	-0.2
Twins	-0.2
Phillies	-0.3
Rays	-0.3
Cardinals	-0.4
Rangers	-0.5
Reds	-0.5
Braves	-0.6
Padres	-0.6
Cubs	-0.9

In first place, having derived the greatest benefit, are the Royals. Ned Yost’s Royals, with a slim lead over the Blue Jays. This doesn’t include the playoffs, but the playoffs also wouldn’t knock the Royals out of first if considered. During the year, Royals non-pitchers attempted 52 sac bunts, as interpreted by Baseball-Reference, and they were a net positive for the team.

This doesn’t capture everything. It doesn’t capture plate appearances that featured a bunt attempt, but wrapped up in another way. It doesn’t capture the odd bunt-for-a-hit attempt with men on. But this does pretty well, and certainly it doesn’t serve as evidence that the bunting was bad for Yost and Kansas City. How did this happen? Well, lots of times, the Royals players dropped down ordinary sacrifices. But one time, Alcides Escobar reached on an error. Jarrod Dyson reached on an error. Escobar also reached on two other errors. There were a total of 13 balls in play ruled singles. It’s so easy to forget that a sac bunt attempt can result in a baserunner, since the whole point is to give yourself up, but it happens, and it can happen pretty often.

Maybe you’d argue that this is Yost getting lucky, that no one plans on the sac bunter reaching. But because it happens, it’s part of the calculation, and if sac bunters never did reach, they wouldn’t be so psychologically appealing. I don’t know how much Yost would bunt if the outs were more assured. I just know what’s actually happened, and this year, those sacrifice bunts have been more good than bad for Kansas City, even ignoring any kind of matchup analysis.

Really, this isn’t just about Yost. Although I’ll mention that, last year, the Royals’ sac bunt attempts also resulted in a positive total WPA. If you look at all of Baseball-Reference’s 2014 sacrifice bunt attempts, you see a cumulative -18.7 WPA. Very bad strategy! But now look what happens when you leave out pitchers: you see a cumulative 0.2 WPA. Essentially, the league broke even, with enough bunters reaching base to offset the outs and various failures. Again, it’s not complete, because we’re missing “expected” WPA and because we don’t know which sac bunt attempts were actually sac bunt attempts, but if you figure this is in the ballpark, suddenly it doesn’t look like managers bunted poorly at all, with their position players. There are bad bunts, but there are also good bunts, and there’s not much you can say to argue with an even WPA. That means, overall, things are neither helping nor hurting.

That’s the league. For the Royals, the bunts have helped. Not in every case, but, overall. And while that doesn’t mean they’ll continue to help in the future, it means Yost hasn’t sunk anything with the bunting to date, and maybe later on one shouldn’t be so quick to be critical. Yost absolutely makes his mistakes, but so do opposing defenses. That’s one of the ways in which a sac bunt can pay off.