Baseball players should ditch the uniforms and dress like the athletes they are

Players are running faster, hitting farther and throwing harder than ever before. And they're doing this all while overcoming a great hindrance -- the very clothes on their backs. The players are the foundation of the game and, currently, the uniforms they play in every day are preventing them from fully showcasing their abilities.
A clear sign that the current uniforms are not optimized for athletic performance is the fact that they haven't changed substantially in your lifetime. Aside from a failed -- and fictional -- bid from George Costanza to change uniforms to cotton in the mid-1990's, no one has even really tried to catch up with the times. Here's what the St. Louis Cardinals looked like in 1930. Add color and this is also what they look like in 2018: 

Meanwhile, here's what football uniforms looked like around the same time, in 1929:

Clearly, baseball uniforms have fallen behind those of other sports in their evolutionary development. Aside from the performance losses, a baggy, unfitted uniform robs the fan of a true appreciation of the aesthetic experience of watching a body dedicated to athletic pursuits move as it has been trained to do. The uniform should showcase the physique of Giancarlo Stanton and also of Billy Hamilton. Both are elite athletes, yet only the former is visibly so in the current uniform.
What should a baseball uniform for the 21st century look like? Let's start by enumerating the motions baseball players go through in a routine game.
Aside from running on the basepaths or in the field, most of baseball consists of arm and core movement in pitching or swinging a bat. On rare occasions, a player will also have to slide into a base or dive for a ball. Therefore, we are looking for a uniform that primarily optimizes running speed -- reduced wind drag -- while permitting unrestricted arm and torso movement. We'll also want something that doesn't hinder a player's ability to slide, dive or leap for a ball.
We can all agree that this has a high drag coefficient while impeding arm movement:

Also, the belt needs to go. When was the last time you went to the gym or ran while wearing the same belt you wear with your jeans? You probably can't remember because it would be a stupid thing to do, because this is what would happen:

Just think how much faster players could run, how much harder they could throw and how much farther they could hit the ball if they didn't have to overcome their uniforms every second of every game!
Now we know two things we don't want in a baseball uniform for the 21st century, but what do we want? Fortunately, we don't have to look far to find athletes who are asked to run, throw, twist their torsos, and jump. This is two-time Olympic gold medalist and former world record holder in the decathlon Ashton Eaton running the 100m.

And throwing a javelin:

Here he is doing the high jump:

and also sliding into the sand in the long jump:

Eaton, more or less, does all the things baseball players do and does them well while wearing a fitted, though not skin-tight, sleeveless shirt with half tights. He changes his shoes for each event and rarely has to make lateral cuts like a player may need to do in the field, so we won't want to replicate that. In this case the bulkier baseball cleat probably makes sense.
Finally, we come to the hat, the most iconic part of a baseball uniform. History prevents us from ditching the cap altogether, but it's obvious it needs some changes. First off, they are too loose, as evidence by the frequency with which they fly off players as they dive for or run after balls in the field. Plus, this moisture retention can't be ideal for performance:

For inspiration, we turn to the SunTrust Park warning track, where The Freeze has been making random fans look silly since 2017. Connected to his speed suit is a hood.

The danger of replicating The Freeze's head wear completely is that his goggles likely obstruct his peripheral vision. That's fine enough for a sprint, but not on a baseball field, where some of the action is to a player's side. To adjust for the loss of the goggles, we could attach a similar hood to our brand-new fitted sleeveless jerseys with the addition of a raincoat-style brim to shield the eyes from sun and rain.
If baseball truly wants its athletes to shine to their full abilities, it will ditch the baggy, heavy and belt-laden uniforms they've been wearing for the past century. It's well past time that players are allowed to wear a uniform that doesn't get in the way of them playing baseball. While it won't hurt that we'll get a better look at the biceps and quads they spend all offseason fine-tuning, the true benefit will be seeing players finally performing at the top of their games.