I noticed something perplexing and perhaps a little startling a while ago while playing around with Baseball Savant’s updated bat tracking data: Los Angeles Angels first baseman Nolan Schanuel ranks 636th among 647 MLB hitters with at least 50 swings in average bat speed (65.1 mph) since arriving in the majors. But it wasn’t the ranking itself, while significantly lower than perhaps expected, that was cofounding, rather it was that Schanuel was the only athlete of his height (6-feet, 4-inches) anywhere near the bottom of the list.
Wingspan, despite its prevalence in sports like basketball and football, isn’t an anatomic measure often assessed in baseball. However, wingspan plays a critical role in metrics such as swing speed for one very important reason: physics. Specifically, velocity, angular acceleration, torque, and moment of inertia.
Let’s Talk Physics
During a swing, athletes rotate around a fixed point (generally in line with their center of mass) to form a quasi-circle with their (straight) bat path. As such, we can apply angular and linear physics to the swing to estimate key factors for producing higher exit velocities (i.e. power). Before circling back to why wingspan is important and ultimately why Schanuel lacks power, let’s look at a couple of equations.
First, linear velocity. Velocity, notated as v, can be measured in different ways but its most basic definition is as the product of displacement over time (v=s/t). The measure of velocity we care about here is in relation to angular acceleration (ω); velocity can also be expressed as v=rω, where r refers to the radius of the circle with which the bat, in this case, is rotating and ω is the rate at which the bat is increasing its rotation speed. This definition is important as it is how MLB measures its swing speed metric. It also tells us that swing speed is proportional to bat length (the longer the bat, the larger the r value) and how quickly the bat rotates.
As noted, how quickly the bat rotates is dependent, in part, on how quickly the athlete rotates about the circle in line with their center of mass; in English, how quickly they turn their hips, trunk, and shoulders. Angular acceleration can be expressed as the torque (t) an athlete produces divided by the moment of inertia (I), or ω=t/I. Torque is the rotational form of force while an object’s moment of inertia dictates its resistance to angular acceleration; the larger the moment of inertia, the more difficult it is to rotationally accelerate that object.
Hold with me, we’re almost done with the math. Moment of inertia can be further defined as the product of the mass of an object and the square of the radius of the circle about which it is rotating (I=mr2). So, we can finally say that angular acceleration is the quotient of torque and the radius of the circle (ω=t/mr2; also written as t=ωmr2)
In short, athletes can produce faster swings by 1. Increasing their bat length (the r in v=rω); 2. Increasing their angular acceleration by producing more torque (i.e. getting stronger; the t in ω=t/mr2); 3. Increasing their angular acceleration by spinning more quickly (i.e. getting more explosive; a smaller r2 in ω=t/mr2); or 4. Increasing their torque by increasing the length of their swing (the t in t=ωmr2).
How The Physics Applies to Schanuel
Option 4 is why Schanuel’s 2nd percentile swing speed is so perplexing. Schanuel is the only athlete among the league’s 20 shortest (19th; 6.6 ft) and slowest swings (12th; 65.1 mph) who is 6’4”, though Cole Tucker (6’3”) and Jacob Wilson (6’2”) are close. All the other athletes are listed at 6’0” or shorter. A general heuristic is that tall people have longer wingspans and, therefore, all else being equal, should produce greater torque values and swing faster.
Schanuel’s lack of swing speed due to having a short swing is a significant reason why he is among the least productive first basemen in MLB, despite a proclivity for getting on base. According to FanGraphs, out of the 38 primary first basemen who have at least 700 plate appearances since 2023, Schanuel ranks 25th in wRC+ (105), 29th in OPS (.710), and 35th in SLG% (.357).
In theory, fixing Schanuel should be easy; increase his swing length and the power should improve. However, a look at Schanuel’s swing mechanics proves that it is more complicated than that.
Below is a video overlaying a still photo of Schanuel and Bryce Harper at ball contact during their hardest hit of the 2024 season (both were home runs). See if you can notice any differences between the two.
First, look at Harper’s lead elbow compared to Schanuel’s. Harper’s is fully extended while Schanuel’s is bent. (For the record: Harper ranks 60th out of 647 in average bat speed (74.6 mph) and 283rd in swing length (7.3 ft); this implies Harper derives a bulk of his power from rotating very quickly.)
Next, look at the degree of bend in Harper’s back leg compared to Schanuel’s. Harper is known for aggressively pushing off his back foot and forcefully extending his front knee during his swings. This produces a powerful rotational vector that opens up his hips quickly and violently. Schanuel, on the other hand, generates less push with his back leg, reducing the speed with his hips open. Looking closely, you can see that Harper’s hips are more open (pointing at the pitcher) than Schanuel’s (pointing more at the shortstop).
Finally, this can be difficult to discern from this angle, but look at the front-to-back angle of Harper’s trunk compared to his legs; his trunk is more or less directly over his center of mass. Now look at Schanuel. It would appear he is leaning backward, shifting his center of mass behind his legs.
I wanted to compare Schanuel’s swing to Harper’s because they play the same position and are roughly the same size; Harper is listed at 6’3” and 210 lbs. Harper’s swing mechanics are more or less perfect for hitting the ball hard, even though he doesn’t have a very long swing. However, what Harper’s swing shows is the importance of r2 in t=ωmr2. Yes, Harper produces a significant angular acceleration, but the mere 8 inch difference in his swing length compared to Schanuel’s can have a drastic impact on torque production because the value is squared.
Is There Hope for a Fix?
According to The Athletic’s Sam Blum on a recent episode of FanGraph’s Effectively Wild podcast, Schanuel has put on 15 lbs of muscle this offseason. In theory, the added strength should improve his angular acceleration and improve his torque. However, until Schanuel changes his swing mechanics, his power will likely remain near the bottom of the first base table.
In early May 2024, MLB.com published a story in which Schanuel attributed his early season slump to such mechanical changes. “I was pulling off the ball, trying to hit homers. I kind of got ahead of myself earlier in the year doing something I’m not used to doing,” Schanuel is quoted as saying. “I need to stick to what I know best and what I do best. And that’s singles up the middle, opposite approach. And if they hang me one and I’m a little early and I get it, I get it.”
However, a look at Schanuel’s Process+ data paints a different story. Schanuel struggled to produce until early July when his decision, contact, and power numbers increased dramatically.
From March 30th until June 30th, a span of 92 days, Schanuel put 87 pulled balls and 52 opposite field balls in play. From July 1st to August 31st, 61 days, Schanuel pulled the ball 58 times and took the ball the other way 30 times. While he didn’t pull the ball more, he did reduce his opposite field contact by 12.9%. Additionally, during the same period, Schanuel’s average exit velocities and launch angles improved to all directions.
Why? It’s possible that teams simply didn’t fear Schanuel’s bat and became more comfortable pitching him inside. However, inside pitches, especially those that are elevated, are prime candidates for Schanuel to crush exactly because his short swing allows him to barrel them up.
Unless and until Schanuel increases his swing length, he will likely continue to struggle against pitchers on the outer and bottom thirds of the plate, leading to an easy scouting report for opposing pitchers to take advantage of. Additionally, unless his swing speed increases, he will likely continue to produce like a bottom-third starting first baseman.
However, Schanuel’s July and August last summer provide hope. Adopting a few mechanical tweaks and committing to pulling the ball, even while struggling, could make facing Schanuel a dangerous proposition.