Bryce Harper’s in a bit of a slump; his 22-game rolling wOBA has tumbled down to a level not seen since 2014. It seems to be a continuation of a trend that started at the end of last season.

Why 22 games? This is why:

Bryce Harper's launch angle has changed dramatically over the last 22 games. Batting .188 pic.twitter.com/q3iWBweDpE — Daren Willman (@darenw) July 28, 2016

Daren Willman, the incomparable overlord of Baseball Savant, tweets out these fantastic radar charts showing launch angle distributions. Harper’s distribution on the right, his first 75 games this year, shows him elevating the ball. His last 22 games show a distribution much lower, favoring ground balls. That shows up in his rolling 22-game ground-ball rate:

The batted ball distribution clearly reflects the launch angle, though perhaps the trend up in ground-ball rate started earlier than 75 games into the season.

Harper is walking a ton and striking out less than last year, but his overall production has gone the way of his launch angles - down. His 116 wRC+ this year is a far cry from his 197 wRC+ last year. Pitchers are throwing more outside and lower than last year out of fear of his power, so Harper just isn’t getting many good pitches to hit. Harper will have to adjust to reverse this slump.