How Do Shifts Affect League-Wide BABIP?

July 26, 2014

I was recently asked the following question [by Rob Neyer]: If infield shifts work so well, why aren't league-wide BABIPs (Batting Average on Balls in Play) dropping? It's a great question. Shifts are designed to to take hits away from certain pull-heavy hitters, and with the huge increase that we have seen in the number of shifts used across baseball over the last few years, intuitively we would think that this would affect the league's batting average. And it does! However, the effect is almost imperceptible because the number of batted balls against a shift is still a small percentage of all batted balls put in play.

First, for reference let's look at what the league-wide BABIP has been over the last 10 years, as well as the shifts data that we have been collecting at Baseball Info Solutions since 2010:

Season BABIP Shifts
2014 .299 13,789*
2013 .297 8,134
2012 .297 4,577
2011 .295 2,357
2010 .297 2,464
2009 .299 -
2008 .300 -
2007 .303 -
2006 .301 -
2005 .295 -

*Projected by year end

Based on research that we have done at BIS, we know that the shift lowers the batting average on grounders and short liners (the ball in play types most affected by the shift) by about 30 points. So far this season, the batting average on grounders and short liners on shifted plays has been .230, and on non-shifted plays it has been .265. That's a significant difference. However, despite the shift being employed far more often this season than any previous season, it has still only been used about 10% of the time. Therefore, the overall batting average on all grounders and short liners in baseball has been .262, only a 3 point difference from the .265 average on non-shifted plays.

And that's just grounders and short liners. If you factor in ALL balls in play, that 3 points gets diluted even further, because the infield shift has no effect on balls hit to the outfield. The league-wide BABIP this season is .299, but it would be .300 without the shifting. So, in general the shift is only going to lower the overall BABIP by about 1 or 2 points, and that gets lost in the noise when looking at year-to-year BABIPs.

However, just because it might be difficult to see the impact that shifting has had when looking at year-to-year numbers doesn't mean that shifting hasn't had a meaningful effect. So far this season teams have saved 127 runs throughout baseball by shifting. If we assume all those runs would have been earned, that means the league's overall ERA of 3.80 would actually be 3.85 if teams weren't shifting. So, the shift does make a difference.

On Tuesday, Tom Verducci published an article for Sports Illustrated supporting the idea that MLB should at least consider making the defensive shift illegal. The thought is that scoring in baseball has declined too much in recent years, so let's regulate the options available to the defense to keep things more exciting for fans. However, as the data above shows, the shift is just a small part of run prevention. A difference of 1 or 2 points in league-wide batting average is nothing compared to, for example, when the pitcher's mound was lowered after the 1968 season. While shifting definitely makes a difference, regulating it isn't going to reverse recent run-scoring trends. In fact, by taking away the shift and limiting the strategies that teams can use to gain an edge, MLB would actually be making the game less exciting.


COMMENTS (9 Comments, most recent shown first)

So now we are going to protect the inability to hit to all fields under the Americans with Disabilities Act? If some 95lber comes up and can't hit the ball out of the infield, can the outfield play shallow?

The fix to this is either in the minor leagues, recognizing and grading this as a serious weakness, or, more simply, the targets of shifts learning a hard bunt to the opposite field and start rolling up doubles. Voila, no more shifts.
2:03 AM Aug 2nd
Verducci must have been hard up for a column. As Bill has pointed out, offensive totals are at or near historical norms. We're already seeing more of a balance between power and speed, as stolen base totals increase as home runs decline. It's becoming a far more interesting game, with more strategic options.

As for the shift, in time this will create more opportunities for hitters who can move the ball around. (Think Wade Boggs and Tony Gwynn.) MLB Network also did a nice feature a few weeks ago that showed the baserunning implications of shifts, and why they may not be used as much in the post-season.

The game evolves and strategies take time to catch up. Let it.
10:56 AM Aug 1st
Verducci: What a sorry case of drumming up a story with misleading stats: no comparison of those left handed hitters to right handed hitters of the same age and skill sets; writing off what adjustments left handed batters have made; etc.

I side with the BJOL readers here. This would be an extreme over-reaction. Heck, I like seeing teams shift (not so crazy about endless throws to first base, but generally agree not letting batters step out of the box so often and limiting trips to the mound are good beginnings to speeding up a game that badly needs speeding up. Limiting commercial time is another pet preference.) It is fun to see the defense strategize so largely and to see batters try to foil it.
7:46 AM Jul 30th
A couple of weeks ago the MLB network broadcast had a constant "Shift" graphic on the screen to show the position of the fielders, just like the count/score/baserunners graphic. It was great -- I was surprised how frequently teams adjusted to different batters -- not just the lefty shift but other hitters too. It really made the broadcast more interesting, and should be encouraged, not discouraged.​
3:03 PM Jul 28th
I would assume shifting occurs most frequently against good batters. Thus the shift might be a valid strategy even if BABIP is higher when the shift is used.

A more useful comparison would be BABIP for the same batters when the shift is used and when it isn't. Even that comparison might have more noise than signal if the shift is used more often is "clutch" situations.
10:14 AM Jul 27th
Do you include bunts in the grounder category?
7:12 AM Jul 27th
I"m not even sure how you'd outlaw the shift. Do you set an arbitrary line for each position that they can't cross? That seems an extreme over-reaction.
7:22 PM Jul 26th
Frankly, the rising strikeout rate has had a much greater effect on scoring. So if Verducci wants to get upset about something, shifts are the wrong something.
6:55 PM Jul 26th
FWIW I'm against rule changes that reduce teams' strategic options, including outlawing the shift, restricting the number of pitchers' throws to first, or limiting the use of relief pitchers. I wouldn't object to refining the balk rule, keeping hitters in the box between pitches, or restricting coaches' mound visits. IMO baseball is the most nearly perfect team sport and any futzing around with it is more likely to make it worse than better.
3:01 PM Jul 26th
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