Three Days of Bunts

We’ve seen three baseball games so far this year, and if that’s a meaningful sample, I think Hyun-Jin Ryu has all the major awards locked up.

We’ve also seen eight plate appearances this season that ended with bunts.  After the jump, a few facts about those bunts, which will accomplish nothing except establishing a baseline for a feature I hope to bring back to these pages with some regularity throughout the summer.

I’ll use the term “bunt” below to represent a plate appearance ending with a bunt.  A player showing bunt and walking or bunting foul twice, only to swing away with two strikes, will not show up here, since Baseball Reference’s play-by-plays only note bunts that result in an out or a player reaching base (or, often, both).  Of the eight bunts we’ve seen in 2014:

5 (62.5%) were bunted by pitchers.  The other three were all by shortstops- Dee Gordon (twice) and Everth Cabrera.

1 (12.5%) was clearly laid down with a base hit in mind.  Gordon bunted to lead off the sixth inning in the second game in Australia last week.  The other seven were in sacrifice situations, so even if the bunter hoped to reach base, the primary motive seemed to be advancing the runner(s).

3 of 7 (42.9%) sacrifice attempts successfully advanced the runners(s).  Others ended in a force out, a foul out, and two strikeouts.

2 of 8 (25%) total bunts put the bunter on first base- Gordon’s hit and Cabrera’s eighth inning sacrifice Sunday night, which forced Brian Wilson’s error, leaving two on with no outs and igniting the game-winning rally.

1 of 4 (25%) of runners advanced via sacrifice scored- Yasmani Grandal, who moved to second on Gordon’s error-inducer, stole third, and scored the go-ahead run on Chris Denorfia’s single.

2 of 8 (25%) total bunts led to an increase in win expectancy for the batting team.  This includes the single and the reached-on-error, but neither of the successful sacrifices dropped by Ryu and Andrew Cashner.

Average change in win expectancy as a result of a bunt has been negative 0.88%, as Wilson’s error was the difference in Sunday night’s game, swinging win expectancy by 10% after all other bunts had averaged a drop in win expectancy of almost 3%.

I’ll try to keep up with these numbers to the best of my ability as the season goes on.  What I’d like to hear from you, dear reader, is how you think the percentages above will compare to year-end trends.  Obviously, very few of the bunts attempted by American League teams will come from pitchers, and the junior circuit bunts far less, so I’ll probably limit the study to National League bunts.

Will more than one in eight bunts come in non-sacrifice situations, perhaps as players try to take advantage of increasing use of defensive shifts?  Will more than a quarter of bunts lead to increased win expectancy?  How will that trend compare to the percentage of runners advanced by bunts who come around to score later in the inning?  Will the average change in win expectancy for the bunting team be positive or negative?  By how much?

You’re up.  Are you laying one down or swinging away?

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30 Comments on "Three Days of Bunts"

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John Autin
Editor

Today, Jeff Samardzija laid one down into a 1-5-3 DP, quashing a 2-on, no-out 5th inning. The Cubs went on to lose, 1-0 in 10 innings.

Samardzija is a .111 hitter, but has 19 sacs in 22 tries, and 7-for-7 with 2 aboard. So I can’t knock that strategy. But I think the majority of sac bunt tries will produce negative WPA.

brp
Guest

If a successful sac bunt by your every day .100/.125/.150 slashing NL pitcher is -3% WPA, what’s them flailing away and striking out on three pitches worth? I’m guessing WPA doesn’t consider the expected outcome of letting your pitcher swing away, but I’ve got to think a sac bunt by the pitcher isn’t a terrible thing.

Now I’m not advocating bunting on a regular basis but it’s got to be more valuable to bunt this year than it was in, say, 1997, and there must be somewhat less negative value in pitcher bunting than pitcher hitting, right?

birtelcom
Editor
The standard WPA calculators and charts are all based on some concept of an average hitter being at the plate. You can’t use those calculators as a guide to deciding whether it makes sense to have a pitcher sac bunt or not (though it will give you the WPA tradeoff, more or less, between the pitcher bunting and a pinch hitter coming in to swing away). The strategy decision between pitcher bunting and pitcher swinging, as brp correctly points out, has to be based on an evaluation of expected WPA if the pitcher swings away vs. if the pitcher bunts,… Read more »
Richard Chester
Guest

I did a quick and dirty incomplete analysis I ran the PI for games in 2013 in which a batter had a SH in his only batting appearance. There were 120 such occasions. 15 of them resulted in a positive WPA and the other 105 resulted in a negative WPA. The best thing to do is to retrieve a WPA calculator via Google and run it for various base-out situations and vary the inning and score differential. I’ll try to do a few.

Richard Chester
Guest
Here are results for some situations from the WPA calculator. First situation: Bottom of the 9th, score tied. Runner on first, no outs: WPA = 0 .72164 After SH, runner on second, one out: WPA = 0.71665. Net change = -0.04486 Second situation: Bottom of the 9th, score tied. Runner on first, one out: WPA = 0.66676 After SH, runner on second, two out: WPA = 0.60575. Net change = – 0.06101 Third situation: Bottom of the 9th, home team down one run Runner on first, no outs: WPA = 0.30902 After SH, runner on second, one out: WPA =… Read more »
Joe
Guest

The numbers don’t quite add up for the first scenario. If the two WPA values are correct, the net change should be -.00499, an order of magnitude smaller than the other scenarios. Interesting that SH still can’t manage to break even in such situations.

Richard Chester
Guest

Thanks for the correction.

Richard Chester
Guest

I should mention that there is more than one website with the WPA calculator. I used the one from the gregstoll site. Tom Tango has the calculator on one of his sites. Try tangotiger.net/welist.html.

eorns
Guest

Interesting that they’re all negative. Though they’re averages. Could a certain type of hitter coming up in the inning make any of them positive?

Artie Z.
Guest
Sacrifice bunts are but one part of the reason the 2013 Red Sox had the AL’s best offense. According to yesterday’s broadcast (I believe it was Sutcliffe but I may be mistaken), the Red Sox do so well because they have a lot of productive outs. In fairness to him, he was including things like “making an out after working the pitcher for a few extra pitches” as productive outs. But still – we deserve better than that. I guess it’s just too obvious to say “The Red Sox scored the most runs because they had the highest OBP and… Read more »
birtelcom
Editor

The Red Sox were second in the AL in 2013 in the average number of pitches per PA that their hitters saw. Twins hitters saw 4.02 pitches per PA on average, while the Red Sox saw 4.01. The league average as a whole was 3.86. The White Sox, at the bottom of the AL in this stat in 2013, saw 3.75 P/PA on average. Although they were very close in P/PA, the Twins averaged 3.79 runs scored per game while the Red Sox averaged 5.27 (league average 4.33).

mosc
Guest

why use WPA instead of RE24? I suppose we miss some late inning leverage stuff but it also makes looking at pitchers bunting when well ahead or well behind more reasonable to evaluate. I’d say when looking at non-pitchers, WPA needs to be considered but for pitchers, RE24 is probably ideal.

Artie Z.
Guest
Your comment may be related to what I just saw – literally just saw. Alex Avila bunted Austin Jackson to 2nd base in the bottom of the 10th inning with zero outs and the score tied 1-1. Whether the Tigers score 1 run or 4 is irrelevant at this point as they just need 1. The RE24 almost certainly decreased in this situation, but the Tigers are not trying to score a ton of runs, but just want 1 for the win. I would guess that neither WPA nor RE24 is exactly what we want in all situations. Sacrifice bunts… Read more »
Artie Z.
Guest
I’m going to try to be more complete in my thought about sacrifice bunts as a “strategic choice”. Runner on 1st, no outs, a successful sac bunt is equivalent to a ground ball to third with the runner moving that ends in a 5-3 putout at first base with the batter being retired and the runner now on second. I would guess that WPA and RE24 don’t really care “what” happened to get to the situation just that we are now at the current situation (I’m thinking of something like a Markov process where the current state is what matters… Read more »
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[…] wrapped up my series on the effectiveness of bunting.  In the comments of past bunt-related screeds I’ve shared in this space, mosc has suggested that I look at this year’s bunting data […]

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