DJ Lema-Who?

The Rockies tend to have hitters with eye-popping stats as a byproduct of playing in Coors Field. This year alone, they have four players with an ISO of .219 or higher (five if you include recent call-up David Dahl). But, on the other side of the offensive equation, there’s only one Rockies player this year who has an OBP over .400. That man is their starting second baseman, DJ LeMahieu.

I noticed that LeMahieu had an above-average .358 OBP last year, but I was ready to dismiss him because he ran an insane .362 BABIP and his walk rate was merely average at 8.1%. Was he really hitting the ball well enough to sustain such a figure? To find out, I looked over a data set of the 253 hitters with at least 200 batted ball events in 2015. LeMahieu had an average exit velocity of 90.6 MPH that year. The average of the group was about 88.9. To put that number in context, LeMahieu had the 60th-hardest exit velocity of the 253. Yes, that number is well above average, but the second-hardest hitter on the list (David Ortiz) only ran a BABIP of .280. To control for the Coors effect, consider this: LeMahieu’s teammate, Nolan Arenado, had an average exit velocity of 91.7, but only ran a .287 BABIP last year. So, LeMahieu’s numbers didn’t appear to be so special, and if his BABIP fell off, there wouldn’t be much left: as I mentioned, his plate discipline was ordinary. In addition, he certainly did not hit for power. He only had a .087 ISO last year, well below the league average of .150. Things didn’t look good for his power behind the scenes either, as his average launch angle was a mere 4.1 degrees; the average for my sample was 10.8. That figure was bad enough for the 244th-highest launch angle out of the 253 hitters in the sample.

So, I wrote off LeMahieu. Boy, was I wrong to do so. This year, his ISO is hovering around league average at .154. His BABIP is an even more insane .383. He’s improved his walk rate to 10.8%, well above league average. He’s also lowered his strikeout rate from 17.3% to 12.9%. This is a huge step for a non-prospect in his age-28 season. What the heck happened?!

For starters, his exit velocity and his launch angle have both improved tremendously. I took a new data set for this year, expanded to include all hitters with at least 150 batted ball events (since the year isn’t quite over yet). There were 255 hitters in the sample. This year, LeMahieu has an improved average exit velocity, at 93.1, which is good enough for 16th out of the 255 hitters in the sample. The average is around 89.4. The average for this group is up 0.5 MPH from my other group, but LeMahieu went up 2.5!

In regards to launch angles, LeMahieu is now at a much improved 5.7 degrees. The new average for this group is around 11.7. So, the group average is 0.9 higher than the other group, but LeMahieu is 1.6 higher! It’s also worth mentioning that in his excellent article published earlier, Andrew Perpetua listed LeMahieu as having the second-lowest percentage (for hitters with at least 300 PAs) of poorly-hit balls. He also had LeMahieu’s xOBA at .388, which is right near his actual wOBA of .391. Lastly, his soft/medium/hard-contact percentages last year (if you prefer this data to exit velocity) were 12.1/61.3/26.6. This year, the soft rate has remained relatively the same, but the medium rate has lost some to the hard. Here’s his contact-quality triple slash: 12.5/51.9/35.6. So, this year LeMahieu’s performance is really not looking fluky. However, one question remains unanswered: what changes did he undergo in order to make this transformation happen?

I think the answer lies in his improving plate discipline. Take a look at the changes across the board from last year to this year:

His O-Swing percentage has improved tremendously the last two years, and is down another 0.9% this year. His Z-Swing% has dropped as well, and though that isn’t a good thing per se, it does illustrate that LeMahieu is implementing a more selective approach at the plate, maybe not swinging at borderline strikes as much. He’s also making a lot more contact – probably because he’s swinging at better pitches, swinging at fewer borderline strikes and fewer balls. The improved contact rate and improved eye has led to a career-best 12.9% strikeout rate and 10.8% walk rate.

In conclusion, I would like to congratulate our friend DJ on proving me wrong. He has earned a lofty BABIP (though his true talent is probably not quite .383, because almost no one’s is). He has made tremendous strides with his batting eye, and that has helped lead to much-improved contact quality and in turn, more power and base hits.

Data is from Baseball Savant and FanGraphs.

Thanks for reading!