You know, I agree with some of what you said about skill, but you're totally losing me with this 'Running baseball player' theory. Running in baseball is pretty much all sprinting? Really? How much sprinting do you think the average baseball player does in a game, anyway?
Let's take a look at James Loney from last night, since I watched the Dodger/Rockie game once the Yankees took a big lead and the little league game ended. He grounded out in the second, so he hopefully sprinted the 90 feet to first base. He hit a homer in the fourth...most likely zero sprinting, but I'll give you that he sprinted the first 45 feet to first base...although he probably didn't. Grounded out to the pitcher in the sixth...zero sprinting. In the ninth he singled do left. He didn't sprint to first. He got caught up in a double play, so let's say he sprinted 80 feet to second base, accounting for his lead.
So in Loney's at bats, that's a total of 215 feet of sprinting. Let's add 100 feet of sprinting on defense, absurd for an infielder and probably generous for an outfielder too, but let's add it anyway. 315 feet total, in probably an average game for a major leaguer. That's 315 feet of sprinting.
I promise you the players on the court or on the ice do 315 feet of sprinting in the first period of every game. Basketball and hockey are not only the marathons baseball is absolutely not, there is also a ton of sprinting, much more so than in baseball. A basketball court is 94 feet long. A hockey rink 200 feet. In case you haven't been watching Sportscenter, basketball is a game of fast breaks. Sprinting. Back and forth. A lot. Hockey is worse.
And whereas baseball virtually always requires only sprinting from point A to point B, in the other sports there are athletic plays to be made while you are sprinting. Twists and turns...sprinting then stopping then sprinting again almost immediately. Much harder on your legs.
Most basketball or hockey players would do the 315 feet of sprinting a baseball player does in a game and not even notice it. Most baseball players, if subjected to the amount of sprinting done in basketball or hockey in a game...would not survive.
Sandra