Today I finally bought the book Moneyball , by Michael Lewis today. I am sure many of you have read it already. I am on the third chapter, in the second chapter, they are going over who to draft and who not to draft. Throughout the chapter, they keep talking about how power can be developed, but the author says plate discipline cannot. I recently have come around to the idea, that a guy like Alcides Escobar, despite his total lack of walks, and power, could one day become decent enough at the plate to warrant an every day spot in the lineup, given his gold glove caliber defense. The point of this thread is not, whether Escobar can, or cannot be an everyday player. I am just wondering, what you guys think are the most likely skills for a player to develop. The things I am really interested in are the 5 tools that everyone talks about, throwing arm, speed, batting average, batting power, and fielding, and also plate discipline, mainly walks, not so much strikeouts. Out of those which are the easiest for a prospect, and which are most likely not going to get any better.