MLB Hitters Get Stuck On Their Backside Too

A lot of my thoughts on hitting are rooted in my own experiences playing, for better or for worse. When I was in school playing ball, I was constantly working through a particular mechanical issue. Traditionally, it is called “getting stuck on the back side,” but I always said I got stuck on a pedestal. When I got to the highest point of my leg kick (which was moderately high), I sometimes transferred too much of my weight over my back foot – it was a swing path killer. Because of my extensive experience with it, I’ve always been keen on identifying hitters who have a similar issue.

Rotational movements like hitting and pitching have linear components, but hitters need to do more than just move on the coronal plane (from left to right or right to left) in order to have a deep entry into the hitting zone. A hitter has to rotate with his hips and/or spine while moving along that linear plane to create rotational power and an ideal bat path. In the case of pedestal hitters, they reach their peak leg lift while sometimes neglecting those other aspects of movement.

Take Will Smith, for example. He uses a high leg kick to create space in his swing and fell into the pedestal hitting habit during the second half of last season:

October 9th

September 22nd

September 7th

A few hittable pitches in the heart of the zone with no barrels to show for it. On the middle-middle heaters, his path was cut off and he only skimmed the bottom of the ball, rather than hitting it flush. That led to can-of-corn fly balls to right field instead of barreled line drives. This was a persistent issue for Smith throughout 2023 – the worst offensive season of his five-year career and the first with an ISO below .200.

When you transfer too much weight over your back foot, you either get stuck and create a path which leads to lazy fly balls to the opposite field or you fall too heavy on your front side and hit grounders like Smith did against Manaea. You lose depth in your bat path and can’t cover as much of the zone with your barrel. For Smith, that negatively impacted his wOBA on outer third pitches. For the bulk of his career, he has been able to cover those pitches, so this should be something he can fix. To do that, he’ll have to get back to his early 2023 swings where he was balanced and creating space for his bat to work through the zone.

April 30th

Smith is a good enough hitter that he still posted a 119 wRC+ last year despite his mechanical flaw. Not everyone has that much room for error, though. Enrique Hernández has had a wRC+ below 75 in consecutive seasons after running a 109 mark in 2021. Like Smith, he typically relies on a big leg kick to create space, rhythm, and timing in his swing. And while the size of his leg kick fluctuates more than Smith’s, it’s still a key driver in his process. Here are a few swings from 2023 before he was traded to the Dodgers:

April 11th

June 25th

July 2nd

Even if you want to cut Hernández some slack on the high quality changeup from Shane McClanahan, that swing is still a good example of how his lack of balance causes him to land heavily on his lead leg. The heavy landing is even more obvious in his swing against Jesse Scholtens in the second clip. With that swing in particular, his leg kick works straight up and down, which causes him to force a lead hip external rotation.

What do I mean by that? If you’re trying to explode your lead leg open, you would create the counter movement (internal hip rotation) first. That way, you’re creating a reciprocal pattern that leads to smooth external rotation. Staying neutral at the beginning of the swing creates an imbalance, causing the hitter to stand on the pedestal instead of rotating into and then out of it as he swings. Hernández has hyper mobile external rotation, which is seen by his tendency to stride open. To control it, he needs to create sufficient counter rotation with his hips. Unsurprisingly, when he went to Los Angeles, he made a clear change in his leg lift that allowed him to stack his center of mass over his midpoint instead of his back leg. Pay attention to the direction he works his leg kick:

August 19th

September 9th

His leg lift started working on an angle towards his back leg, which allowed him to have a controlled explosion and balanced swing. With the Dodgers, he had a 96 wRC+ – much more in line with his career 94 mark. Yes, it was over a sample of 185 plate appearances, but the movement quality improvement is undeniable.

The last example I’ll use to portray pedestal hitters is Guardians outfielder Steven Kwan. His case is a bit more complicated. In his rookie season, he splashed onto the scene with a 126 wRC+. However, his peripherals suggested there would likely be a regression – his .341 wOBA was considerably higher than his .312 xwOBA. In 2023, those numbers almost completely converged. He had a .313 wOBA and .318 xwOBA. From a mechanical point of view, this wasn’t completely surprising.

His big leg kick is a crucial component of his swing. It keeps him stable, which plays a key role in his great plate discipline. However, the movement also makes him heavily reliant on his hands to do most of the work to get on plane. Given his elite bat-to-ball skills, he can successfully do that more than other players, but he doesn’t have much room for error. If he gets stuck on his back side, his hands can only do so much. If he identifies a pitch too late, even just slightly, then he puts himself in a tough position to make flush contact. Here are a few swings showing that:

July 9th

August 30th

September 22nd

Each of these fastballs were thrown between 96 and 97 mph, but were right down the middle. Kwan couldn’t get his hands on plane despite the hittable locations. This was a trend for him all year. In 2023, he saw 190 four-seamers with a velocity of at least 96 mph and had a .155 wOBA against them. This is another example of why rotational hitters like Kwan, Hernández and Smith need to be on top of their mechanics at all times. Pedestal hitting gives batters even less margin for error than other hitters against high velocity.

Every hitter has his weakness, and for this trio of players, theirs is directly related to how they load with their leg kick. As I watch each of them in 2024, I’ll be looking for any potential adjustments they might have made over the offseason, or might make as the season progresses.