Jason Kipnis has found more power than he ever had before

Jason Kipnis was one of the best second basemen in MLB last year, as he hit .303/.372/.451 and played solid defense. His batting average and walk rate are each down a little this year, but he's largely made up for that by hitting with far more power than in any other season during his career.

Kipnis' slugging percentage right now is . 479; his career high is .452. His isolated power figure at the moment is .199, as compared to a career high of .168. His career high in home runs is 17, but with 70 games still to come this season, he's already hit 15 of them, putting him on track to fly past his previous best. His 37 extra-base hits this year are second on the team behind only Carlos Santana's 39, and put Kipnis on pace for 65, which would also be a career high.

Kipnis' wRC+ this season is 119, which is not quite as high as the 127 he posted in 2013, when he set all the above-mentioned career bests, or as the 126 he put up a year ago. Kipnis isn't having the best offensive season of his career, but he's having a very good one, and it's of a different sort than those two. Noticing that, I wondered what underlying differences might have led to the big uptick in power he's shown, and I set out to try and find out.

Kipnis' walk rate last year was 8.9%, this year it's down to 8.0%. His strikeout rate was 16.7%, it's up to 20.9%. PITCHf/x has his swing rate down from 43.1% to 42.0%, which might make it a bit surprising that he's walking less and striking out more, but he's also being thrown slightly more pitches in the zone, and he's swinging-and-missing a bit more.

Kipnis made soft contact 15.4% of the time last year (according to the numbers on his FanGraphs page), but that's down to 12.5% so far this season. His medium contact is down a little bit too. That leaves only hard contact, which is up from 30.6% in 2015 to 35.9% this year.

He's also going to the opposite field less often, down from 28.6% last year to 22.8% this season. Some of those balls are instead being hit to center, but most of them are being pulled to right, which is where almost all of his home runs have been hit.

The biggest difference I see though, is in his batted-ball profile: Last year Kipnis' ground ball rate was 45.0%, but that's down to 38.0% this year, by far the lowest of his career. Those grounders have been replaced by fly balls, as his FB rate has spiked from 28.1% to 35.9%. Meanwhile, 15.2% of his fly balls have been home runs, as compared to his career rate of 10.2% and a 2015 rate of just 6.9%.

It's worth remembering that Kipnis has a slow start at the plate this year. In his last 40 games though, dating back to June 1, he's batting .299/.375/.554, with a .255 ISO and a wRC+ of 149, and he's done that with a BABIP of .339, not really out of line with the .330 BABIP he's posted from the beginning of 2013 until now. During this stretch, he's made soft contact just 9.5% of the time, and has made hard contact 37.3% of the time. He's hit grounders just 32.0% of the time, and has hit fly balls 41.8% of the time.

Here's a chart with Kipnis' figures for these metrics last season, this season, and the last seven weeks:

The last seven weeks have seen a return to his more typical spray distribution, but he's hitting the ball even harder and elevating it even more. Those seem to be the keys. His HR/FB spike gives him the highest figure of his career, but it still only put him in the 59th percentile of qualified hitters, so it's not as though it's some unsustainably high figure, even if regression means it's likely to dip a bit.

In short, the power increase seems real to me, and is a solid tradeoff for the small decline in his walk rate and increase in his strikeouts. Factor in his continued solid defense, and Jason Kipnis once again among the best second basemen in baseball, even if he's a somewhat different sort of player.