Q. OK, he's got some PWR and he's got HIT at the same time. Is that realllllly so unusual?
A. Bill James wrote an article re-interpreting the McCracken premise (BABIP) and the Fangraphs-style GB, LD, FB, CT% etc and he started with this...
What makes hitters different from each other is four things. How many pitches they take, how often they hit the ball when they swing, how HARD they hit the ball, and how often they pull it.
Groundballs, they all hit .250 (or whatever). Line drives, they all hit .750 or whatever. Fly balls the other way, that's about the same too. But good hitters pull the ball in the air a lot ...
You get the idea. When you are talking about a hitter who can swing hard and still square the ball up, you're talking about a hitter who is simply a superior species. That's what the scouts are talking about.
Q. Couldn't you totally capture PWR x HIT by simply counting up K% and ISO, as in this approach?
A. No, you couldn't. Thanks for asking.
That is a great set of data to have, the data in that article. If there were 12 pieces of paper on your desk, and you were trying to project Jesus Montero, you would want that piece of paper to be one of the 12 pieces. Dr D's problem comes when we say that it is the only piece of paper we want, that such a simplistic answer is the "correct" one.
There are many reasons that ISO and CT% do not capture a minor leaguer's PWR and HIT tools:
(1) The minor leaguer is a moving target, a player who is evolving. A snapshot now will not capture his 2014 skills. Some minor leaguers who are now at 18% K's will be at 15% two years from now; others will be at 21%.
(2) CT% does not completely capture the baseball HIT tool.
(3) Even if ten players had exactly the same stats at exactly the same age and level, they would diverge later.
Q. What do you mean, CT% and K% don't capture a HIT skill? How could that be?
A. Why don't we separate that out. Here y'go amig-O.
In the meantime, here is one vid on the PWR and one on the hit. Check out this opposite-field HR: Montero gets the front hip into it and the OF's stand and watch. On an opposite-field HR?
But then, check this out. Here he goes down for a low-away pitcher's pitch; Edgar might have reached out and shot it into the right-center gap. Jesus Montero gives you the Montero version of Edgar.