Was DJ LeMahieu’s hot streak sustainable?

It’s been a long season for the Yankees. With their FanGraphs’ playoff odds dwindling into the mid-teens, and a lack of new assets thanks to some trade deadline inaction, it’s time to take stock of just how much every player on a roster full of aging veterans will contribute going forward. The likes of Anthony Rizzo, Giancarlo Stanton, and DJ LeMahieu are all on the books for at least next season; how much can they reasonably be expected to produce?

The remaining length of this season, though it may mean prolonged suffering for the fans, is also positive in that there’s still ample time for any of these guys to put together a hot stretch and carry some momentum into next year. One of those guys, LeMahieu, has already been streaking.

In June, LeMahieu’s 44 wRC+ tied for 263rd among the 290 hitters with at least 50 plate appearances that month. He was also the worst Yankee, edging out Stanton (45 wRC+) and Rizzo (60). The utilityman’s cold stretch extended into the beginning of July, but over the past 30 days, he’s looked like a different man. His 145 wRC+ over that span has been the Yankees’ second-best (trailing only Gleyber Torres’ 152 mark) and puts him above the third quartile league-wide. Most impressive is his .427 OBP in that stretch, which has ranked 23rd out of 269 major-league qualifiers.

As Andrés wrote back in June, The Machine’s struggles that month came with putrid plate discipline as well as contact rates unheard of for the two-time batting champ. This was especially shocking given that hurlers were throwing him pitches in the zone more often than they had at any point in his Yankees’ tenure:

This year, LeMahieu’s swing rate has been a lagging indicator of opposing pitcher zone rate. That is, as the zone rate has gone up or down, the utilityman’s swing rate has followed. Clearly, pitchers noticed LeMahieu’s diminished production beginning in May, and he ultimately finished the month 33 points of wRC+ worse (78 versus 111) than in March/April. Pitchers had elected to challenge him more often — their rolling zone rate reached a peak of 55.2 percent on June 3rd. LeMahieu’s rolling swing rate, meanwhile, was up to 46.8 percent by that point, but while the zone rate came crashing down thereafter, the swing rate shot back up to 48.1 percent on June 25th after a brief dip — hence the lag — before eventually reaching the depths it now stands at (34 percent as of my writing).

It’s frustrating for a player when they begin to decline. Especially for a guy like LeMahieu, who’s never really had to tinker with his mechanics much, it can be exasperating when what used to come naturally simply doesn’t anymore. I imagine those feelings only got worse as pitchers started pounding the zone; it’s almost a sign of disrespect to the veteran, that hurlers felt so comfortable challenging him. Yet, he couldn’t rise to the occasion — in fact, his production really only rebounded when pitchers started to shy away from the zone again. Here’s the same graph from above, but with wOBA (weighted on-base average) as a proxy for production:

Pitchers were still finding success against LeMahieu even when he caught onto their zone-pounding strategy. But given that changes in his swing rate have lagged behind pitchers’ changes in zone rate, hurlers probably figured they could start pitching LeMahieu out of the zone again and get a few extra chases before he caught on. Yet, as soon as they stopped challenging him, his production started to improve, and when his swing rate caught up with the zone rate, his production surged.

Now, with his swing rate in the trenches again and a calf injury with the potential to nag, pitchers will probably return to challenging LeMahieu. But there is some reason to hope that his turnaround wasn’t just a product of him not swinging when pitchers started throwing more balls.

Specifically, when LeMahieu has swung lately, he’s swung at better pitches to hit. When his swing percentage peaked on June 25th, his chase rate stood at 25.1 percent and his rate of swings on pitches in the zone (Z-Swing) was 54 percent. Since, he’s dropped his chase rate by 5.2 percentage points while his Z-Swing has dropped just 1.6 points. From a proportional perspective, the improvement is especially clear: his chase rate has dropped by over 20 percent while his Z-Swing has dropped just about three percent.

Perhaps the frustration got to LeMahieu a bit, interfering with his pitch-recognition ability. Maybe the Yankees told him to swing more when pitchers were still throwing in the zone, and he became less selective in the worst way. Whatever the cause, it will be interesting to see how pitchers approach the infielder going forward. Will they seek to challenge him again, since that strategy has had success this season? Or will they continue pitching more tentatively, especially since he’s become a more dangerous hitter of late?

The truth is, even limiting our scope to just his recent 30-day hot streak, LeMahieu still isn’t hitting the ball with authority: his barrel and hard-hit rates are both below-average among hitters with at least 50 plate appearances in that stretch. So, if pitchers do choose to challenge him again, he won’t beat them by swinging more like he did last time. The best hope is that his plate discipline improvements will carry over, which is a possibility if he’s feeling less frustrated. Either way, though his best days are likely behind him and we should lower our expectations, if he can continue honing his plate discipline, LeMahieu can still be productive. There is a path forward for the veteran; it’s just not what the Yankees may have envisioned.

Stats are as of end of day Tuesday, August 8th.