Rubbing Mud: The Year of the Long Single

On May 24, Michael Conforto had a very good game. It wasn’t quite as good as the game he had the night before, when he launched two home runs and had three total hits, but he did have two singles and two walks. (Facing the Padres is going to make a lot of very good hitters look superhuman, before the year is out.)

There’s even better news, if you’re a Conforto fan: one of those singles really had no business being just a single.

That rocket toward the gap in right-center field was hit at 102.8 miles per hour and had a launch angle of 16.1 degrees. Here’s how balls hit roughly that way have turned out, during the three seasons of the dawning Statcast Era:

(The 2017 data is through games of May 29.)

The batting average on balls hit this way (between 102 and 103 miles per hour, with a launch angle between 16 and 17 degrees; we’re obviously talking about a very small sample) has varied widely, and this year’s figure sits right between those of the last two years. The constant, though, is a trend toward fewer such batted balls turning into extra-base hits. Widen the lens, and you can see that the phenomenon is real.

Long Singles as a Percentage of Singles, 2015-17

That’s not hard to explain. For one thing, the league gets more efficient all the time when it comes to turning ground balls into outs. The league-wide BABIP on ground balls was .250 last year, but is .248 this season. For another, infielders are (on average) playing fractionally deeper, taking away some would-be bloop hits. Hitters, for their part, aren’t looking for singles very often anymore. The fly-ball revolution has made power the end-all, be-all of modern offense.

On 17 occasions this year, a team has seen home runs account for at least half their hits. That puts us right on pace to break the record for such games, which is last season’s total of 50. Before that, the record figure had been 35. Before 2015, only one season had seen more than 28 such occurrences.

Back to Conforto’s scalded single to Hunter Renfroe, though. It really does seem to be emblematic of the ongoing changes in the way the game is played—especially the way offensive and defensive strategies interact. Renfroe isn’t noted for his defense, but he’s an impressive athlete. He also didn’t have to range especially far to get to Conforto’s liner—he just had to cover it fast.

This is the newest innovation in run prevention. Teams are demanding ever-increasing athleticism from their corner outfielders. (Go ahead and compare Kyle Schwarber to his current peers, then try to do the same with the left fielders of 2003.) Outfielders are playing deeper. They’re being shifted and shaded more aggressively.

Average Starting Distance on Batted Balls for Center Fielders

As batters look to drive the ball more, and as pitchers come to understand the value of cutting off extra-base hits, we’re seeing many fewer singles. We’d be seeing fewer still, though, if it weren’t for the fact that defenses are starting to turn doubles and triples into singles, instead of trying to turn the occasional blooper from a single into an out. By 2018, the long single spike of 2017 might well feel quaint.