58,000 balls were hit into the shift last season. In 2013 there were 6,900.
I read the article that published that stat (can't remember where). The author didn't make clear if that was 58,000 balls literally hit at shifted fielders, or if it was 58,000 balls put in play when the team in the field had a shift on. But I'm pretty sure it's the latter.
Justin Choi at FanGraphs has an article up about banning the shift (it doesn't mention that stat).
https://blogs.fangraphs.com/what-banning-the-shift-does-and-does-not-accomplish/. Here are some conclusions:
"The hitters with a tendency to pull their grounders often record the lowest groundball rates. In other words, the hitter who seem like beneficiaries of a shift-less environment don’t actually have much to gain. If anything, removing the shift also removes the downside in adopting a pull-heavy, air-oriented approach, and if we’re to believe that strikeouts go hand-in-hand with “launch angle” swings, a ban on the shift likely won’t have the desired effect.
So are shifts irrelevant to strikeout rates? Not at all! In fact, the shift’s ability to influence them might be its greatest strength — and weakness. Russell Carleton of
Baseball Prospectus is the foremost expert on the shift, and one of his many discoveries is how it
disproportionately affects left- and right-handed batters. To provide a brief summary: the shift produces an unintentional “walk penalty” due to pitchers’ tendencies to nibble around the edges with a shift behind them. Lefties swing more often with the shift on, though, and see an increase in strikeouts from chasing outside the zone. But righties swing
less often with the shift on, leading to fewer strikeouts and more walks.
All in all, it’s safe to assume the shift is a responsible for a slight increase in strikeouts, since lefties and righties don’t cancel each other out completely. But the emphasis is on “slight.” While writing this article, Carleton published
his own thoughts on the proposed shift ban, in which he estimated the league-wide reduction in strikeouts to be a “per PA rate of 0.4 percent.” That’s an extremely small decrease, one that no human would notice unless it were pointed out to them. It tracks with the data on batted balls from earlier. BABIP has gone down, but to an extent only visible on a spreadsheet.
So what a ban on the infield shift accomplishes is two things. One, it restores a sense of normalcy to the game. No longer is a ball yanked past the three hole an automatic out, and no longer is a bunt against a shift an automatic single or double. Two, it buoys the production of a specific group of hitters, which probably includes at least one lefty from your favorite team. What it won’t accomplish is becoming a cure-all for MLB’s strikeout or pace-of-play ailments. Even with those pesky shifts gone, the game should hum along as usual. Sounds like a lot of hoopla about a strategic choice."