Because of that, it might seem reasonable to place equal blame on the hitters and pitchers for the increase in strikeouts. It's possible to place some blame on the batters for increasingly swinging at pitches outside the strike zone, but contact on pitches outside the zone actually went up with O-Swing percentage a decade ago, and it wasn't until after the swing rate hit a plateau that contact rate moved down over the last few seasons. To put these changes in more concrete terms, let's take the numbers from 2013, where hitters swung at 30.3% of pitches outside the zone and made contact 66.5% of the time. If the change in whiff rate over the last five years isn't due to hitters chasing pitches outside the zone, then what is the cause of the climb in whiffs and strikeouts? 14 percentage points in whiff rate, which is more than the change on hitters chasing pitches out of the zone. The big problem for hitters is that breaking pitches have always induced more whiffs. While hitters have been forced to adapt/take advantage of the juiced ball and potentially avoid shifts by hitting over them, a good portion of this rise in strikeouts was inevitable due to increasingly more talented pitching.