Will Fernando Tatís Jr.’s New Two-Handed Finish Keep Him Healthy?
Athleticism. That’s Fernando Tatís Jr.’s game. He has all five tools. Underneath those tools are an additional two , and probably more: plate discipline and adjustability. Adjustability means the skill to make swing adjustments on a short- or long-term basis. Athleticism makes these two things a lot easier, especially adjustability. Why? Your body has an advanced feel for acquiring skills.
When conducting motion analyses, it’s common to recommend a player to change a movement pattern for the sake of efficiency and/or injury prevention. Unfortunately, Tatís Jr. suffered a left shoulder subluxation earlier this season. Quoting Dr. Rodney Benner who recently spoke to CBS Sports, “A shoulder subluxation is when the ball comes partially out of the socket and returns back into place immediately.” An important thing to note about shoulder subluxation is that once your shoulder comes out of place once, it is significantly more likely to do so again. I’m not a professional athlete, but I myself suffered from a shoulder subluxation on the baseball field during my college playing days. Similar to Tatís, I did not opt for surgery and chose rehab.
During my quest to discover how to best take care of my shoulder, I discovered what people in the biomechanics field refer to as deceleration. When throwing or swinging, the body needs the brakes to be just as strong as the accelerators. With weak brakes, the body will just keep spinning. Depending on the speed of the “spinning” one can risk potential injury if they don’t have strong brakes. This parallels directly to Tatís, who has god level bat speed. Let’s take a look at the swing that sent him down. Sorry to show this, but it perfectly portrays what I’m referencing.
When you’re swinging this fast, you need effective brakes. Just a few swings earlier in the at bat, Tatís did exactly that.
After the swing and miss, he controls the finish using his hands as the brakes. Throughout a hitter’s swing (or any movement), different body parts move in unison. A hitter’s goal should be to transfer energy through their body without disproportionately applying force with a single part of their body. Any movement in a swing must be countered with a reciprocal movement to control the transfer of energy. Acceleration pairs with deceleration. To counter the unique speed in which Tatís Jr.’s torso is moving, he must create some sort of deceleration pattern to ensure he is not overstressing, or in this case over-rotating, any particular part of his body. Decelerating in the swing occurs through the hips and torso. When the stride foot hits the ground, the hips stop. That gives a hitter a quick moment to adjust to a pitch with their torso and make a swing decision. The more effective the deceleration patterns, the better chance to make contact.
When a hitter does this, not only is there an enhanced chance to make contact, but there is less chance of injury. But in this instance, Tatís Jr. swung through with one hand, completely selling out on the pitch. While this is not necessarily something he does all the time, he’s done it long enough to have shoulder issues since he was in rookie ball. On the surface, this seemed like an acute event, but his previous injury history suggests that this may be a chronic issue. Has he partaken in the sellout one-handed swing one too many times? Well, I have not watched enough to know. I am also not a doctor and don’t have motion analysis data on the talented Padres shortstop.
However, people close to Tatís Jr. seem to be aware of how this type of swing may affect somebody with chronic shoulder issues and they have suggested some adjustments which might help Tatís Jr. in the long run. In particular, the two-handed finish. Usually, this type of swing adjustment is implemented over time, but Tatís Jr. is an exception. He managed to implement it overnight. Remember that thing I said about athleticism? He acquires skills very quickly. He makes adjustments quickly which allow him to pick up on skills faster than the average player. Here’s an equation for you.
Athleticism + proprioception (feel for one’s body) = Advanced skill acquisition
I tried sorting through Tatís Jr.’s swings this and last year to find any changes. Like I said, he doesn’t usually finish with one hand. So, on my first look, I was confused at what Jayce Tingler was referencing since Tatís’ norm is the two-handed finish. After further inspection, and in particular one swing, it became more obvious what was different about the two-handed finish. Here is his first homerun from 2021 before the subluxation.
Normal two-handed finish. Well, normal relative to himself. It’s still a pretty aggressive follow through. Now here’s his homer off Dustin May from last week.
It might be tough to pick up on, but this finish is noticeably different. In fact, it reminds me of some hitters with superb deceleration in their swings. Check it out.
These were the first three players that popped in my head when I saw Tatís Jr.’s finish, and to me, they all look like they are intentionally trying to stop the swing after contact. Another way to say this is this they are actively trying to not over-rotate or roll over. Very similar to a hockey player shooting the puck. When Alex Ovechkin shoots, he doesn’t spin out of control. He stops his stick at an optimal point. It helps him with both body control and shot accuracy. Here it is.
It’s fascinating how one little change can have such a positive effect on movement quality. Not to say that Tatís Jr.’s movement was bad in the past. It’s more that we know of his injury history and have a good reason to believe making a change that will have a positive effect on his body without sacrificing on field performance. We don’t want to make any lofty assertions but there is no doubt that whoever is working at the Padres knows the effect that deceleration, or lack thereof, can have on a rotational athlete, especially one that produces force with the speed of baseball’s brightest star.
The change has had a bit of an effect on his batted profile in the early days too. I must stress very very early days. He has had 44 batted balls this season. While that’s about 10% of his career batted balls, it’s still not enough for us to know whether the change is permanent. The major impact is that he’s pulling the ball more frequently than he has in the past. In 2019, he pulled 37% of his batted balls. There wasn’t much change in 2020 either when he pulled 36.6% of the time. However, this year his pull rate is up to 52.3%! Wowza. The swing is the same other than the changed finish, so it’s tough to tell what exactly is causing this. Maybe it’s the change in mentality that he needs to control his finish more? Maybe not. Is he swinging at different pitches? Take a look below. The first image is 2020, then followed by 2021.
There are certainly some differences. The swing decisions are coming about in his batted profile as well. He’s almost exclusively hit the ball successfully to the pull side.
Is it possible that the subtle mechanical change influenced his swing to this extent? It cannot be ruled out as a potential reason. An increase in Pull % from 36.6% to 50% is nothing to scoff at. As I said previously, Tatís Jr. adjusts quickly, and this could have very well been part of his preseason plan. Either way, his mechanics have changed along with this batted ball profile. But again, it’s early and most likely too soon to make any strong conclusions. That’s the scope of another article in the future when we have a little bit more information. Yet, it’s interesting to think about how a slight mental/physical change can alter batted ball outcomes. For now, we hope that this mechanical change prevents any further damage to the young star’s shoulder.
Lots of folks are concerned. Concerned that the Padres are making a mistake by not having the current face of the game get surgery now, so that we all get to enjoy him more later. But honestly, I’m not too sure I’m willing to say surgery is inevitable at this point. The first reason is because I’m not a doctor and am not qualified to say so. The more important second reason is that we are dealing with a special athlete. An athlete who made a difficult adjustment by simply thinking about it more. If we had motion data, we could perhaps infer if the stress on his shoulder has changed or decreased in response to the mechanical adjustment. In due time, we will have Hawk-Eye data which allows us to do so. Till then, the public is left guessing, or educated guessing?
All statistics and Visualizations courtesy of Baseball Savant and FanGraphs
