Blog post

A closer look at Luis Robert’s post-injury escape

Luis Robert made his 2020 debut as our No.7 prospect in baseball and had a strong rookie season with league average offensive numbers (100 wRC +) and stellar central field defense (8 runs. defenses saved), helping the White Sox return to the playoffs. Under the hood, however, there were a few red flags. He had the worst SwStr% in baseball at 22.1%, along with a strikeout rate of 32.2%. His O-Swing rate of 43.1% was the fourth worst in baseball, and even when he made contact he had a below-average exit speed of just 87.9 mph. The 2021 season started off with a similar level of production until Robert suffered a hip flexor tear in early May that would end up costing him the middle three months of the season.

When he returned to action in early August, he immediately looked like a different hitter, posting a 173 wRC + over the remainder of the season and, perhaps most impressive of all, dropping his SwStr% down to 14. , 5% – not quite league average, but far from the outlier it had been before his injury. Check out the contrast in his career numbers before and after his injury:

Robert’s career divisions

Pre-injury Post-injury
Pennsylvania 330 193
MEAN .259 .350
OBP .320 .389
SLG .444 .622
wOBA .327 .424
BB% 8.2% 3.6%
K% 30.6% 17.1%
SwStr% 21.5% 14.5%
Exit Bike 88.3 92.0
Barrel% 11.9% 13.5%

As you can see, his garish offensive performances are now supported by a huge improvement in his strikeout rate, as well as a much better quality of contact.

Ultimately, while Robert was sidelined by his injury, he was doing more than just working on his recovery; he was also working with batting coach Frank Menichino on a few adjustments to his stance and approach. The Cuban outfielder spoke to James Fegan of The Athletic in late August:

“I haven’t made any big changes. Maybe my front foot is a little open to the left, but barely. The only thing I have changed is my approach with two strikes. I started earlier, but it’s honestly the biggest and the only change I’ve made to my position.

There’s a lot to analyze out there, but let’s start with his legs. He indeed returned from his injury with a more open position; watch how it became more and more open as the season progressed:

I think Robert liked the result of opening his position so much that he kept expanding it. Now why did he like the result? From the side you can start to see what this open position helps him accomplish with his hips:

The open position forces his leg to move towards the plate with less movement towards his back leg. Less backward movement causes her hips to twist less. The stance allows her to keep the big leg kick as a timing mechanism, but the movement no longer locks her hips, creating a faster drive towards the ball.

Regarding the part of his quote on a two-step adjustment, I can’t say exactly that I saw much, on video or in his stats, to support a specific change there. I think it reveals a conscious effort to make more contact, though, which has likely bled into his overall approach, especially if the new position shortens his drive towards the ball. His low hit rate in two-hit counts after returning (13.2%) was slightly better than outside of those counts (15%), but his overall swing rate was much better after those adjustments (21 , 5% to 14.5%). ). It wasn’t just a two-hit improvement in his touch; he hit the ball more often at all levels.

One of the biggest areas of improvement for Robert was his ability to punish fastballs. It was his worst pitch type and an early weakness, with a 16.9% puff rate and below average overall performance. Fastballs aren’t exactly a swing-and-miss pitch: the league’s average puff rate for all types is only 8.7%. But after this positional adjustment, Robert crushed the fastballs, lowering his SwStr% to 10.8%.

Performance against fast balls

Pre-adjustment Post adjustment
BA .241 .404
OBP .317 .454
SLG .352 .727
wOBA .297 .495
Exit Bike 90.7 93.1
SwStr% 16.90% 10.80%

SOURCE: Baseball scholar

Wrestling with fastballs is usually a sign that a batter’s swing may be a little too long. Improved contact and the overall increase in production suggest that Robert is now better suited to catch up speed. It was a remarkable turnaround for him, one of baseball’s top fastball hitters over the past two months.

Unlocking more contact is one way to improve discipline at home plate, but a more fundamental skill is the ability to make good decisions about what to hit on. This is where Robert struggled throughout his young career, and even in his scorching second half he showed little improvement in this area. Since his beginnings, he has led baseball in Swing% and first pitch swing; both increased after returning from injury. The swing isn’t objectively bad (although our Devan Fink has some interesting thoughts on that), but it’s hard to be a really good hitter when you swing as often as Robert. The following graph represents the Swing% to wOBA for each season since 2015, at least 250 plate appearances:

Robert is an outlier in terms of being extremely productive with such a high swing rate. The problem for him is that this aggressiveness isn’t just contained in the strike zone; Even after his return, he still had one of the highest O-Swing rates in baseball:

Plate discipline

Pre-adjustment Post adjustment
Zoned% 37.9% 40.5%
Swing% 58.5% 61.3%
Z-swing% 82.0% 88.4%
O-Swing% 44.2% 42.9%
SwStr% 21.3% 14.5%

Robert’s O-Swing% showed minor improvement but was still too high and could hold him back if pitchers teased him more than they are now. He’s actually seen more land in the Zone (Zone%) over the course of the season (and saw a roughly league average Zone% last season), which seems like a mistake the league will make. not next season. What will happen when pitchers start treating him closer to Javier Báez and he starts to see an area% more worthy of his aggression? That’s where he needs to continue to grow and adapt, and I imagine the pitchers will force the problem on him next season.

Robert made some notable improvements in 2021, which is a testament to his ability to make more improvements in the future, and we still haven’t seen a full season of him yet. His elite defense and explosive bat will keep his ground surprisingly high; just look at his 4.7 WAR career in 523 plates. If he can develop a little more patience outside of the strike zone, we might consider an MVP candidate in the years to come.