This is somewhat off topic, but I found this a very interesting study of what makes a good athlete. In baseball, so much of it is experience and being able to see the rotation of the laces of a ball for a split second and then predict where it is going to go. The skill is so sport specific that the below happened. The marine test should probably be similarly specific to the activities infantry has to perform: 100m buddy carry, 10 mile ruck with full pack, and I’d think pull ups stay.
“As part of the pregame festivities, a raft of major league stars had tested their skill against Finch’s underhand rockets. Thrown from a mound 43 feet away and traveling at speeds above 65 mph, Finch’s pitches take about the same time to reach home plate as a 95-mph fastball does from the standard baseball mound, 60’ 6” away. A 95-mph pitch is fast, certainly, but routine for pro baseball players. Plus, the softball is larger, which should make it easier to hit.
Nonetheless, with each windmill motion of her arm, Finch had blown all her pitches by the bemused men. When Albert Pujols, one of the greatest hitters of his generation, stepped forward to face Finch during that practice, the other major leaguers crowded around to gawk. Finch adjusted her pony-tail nervously. A smile stole across her face. She was exhilarated, but she was also afraid that Pujols would hit a line drive right back at her. A silver chain dangled over his expansive chest; each of his forearms was wider than the barrel of the bat.
“All right,” Pujols said softly, indicating he was ready.
Finch rocked back and then forward, whipping her arm in a giant circle. She fired the first pitch just high. Pujols lurched backward, startled by what he saw. Finch giggled.
She unleashed another fastball, this time high and inside. Pujols spun defensively, turning his head away. Behind him, his professional peers guffawed.
Pujols stepped out of the batter’s box, composed himself and stepped back in. He twisted his feet into the dirt and stared back at Finch.
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The next pitch came right down the middle. Pujols uncoiled a violent swing. The ball sailed past his bat, and the spectators hooted.
The next pitch was way outside, and Pujols let it go. The one after that was another strike, and Pujols whiffed again. With one strike remaining, Pujols moved to the back of the batter’s box and dug in, crouching low in his stance.
Finch rocked and fired. Pujols missed badly. He turned and walked away, toward his tittering teammates. Then he stopped, bewildered. He turned back to Finch, doffed his cap and continued on his way.
“I never want to experience that again,” he later said."
http://sportsillustrated.cnn.com/more/news/20130724/the-sports-gene-excerpt/