Like most fans, I enjoy watching young players and trying to figure out whether they will get better, never progress, get worse. Some guys, like Brett Anderson, will make big strides, some guys, like Travis Buck, will suddenly stall, some guys, like Eric Patterson, will keep getting new chances with old results, and some guys, like Trevor Cahill, and Vin Mazzaro, and Aaron Cunningham, will...? Here's what I think makes projecting future performance so especially tricky. I had Dallas Braden pegged as a 4th starter because while I liked his demeanor, fastball command, and changeup, I also saw that his fastball lacked great movement, and that his only other weapon, a curve, was primarily effective against lefties but that did he didn't have a lot of weapons against right-handed batters other than to spot the fastball and pull the string with the changeup. And on this one, I don't think I was exactly wrong. The Braden I projected was a different Braden than the one who has taken the mound in 2009. He learned to add and subtract on the fastball and then he learned a cutter, and I think this pitcher has a chance to be more than a 4th starter. So how do you look at a drafted player, or a young player you see in the big leagues, and project whether or not they will able to add new skills that might elevate their game in important ways? Will Cahill be able to repeat his delivery better, in which case the pitches he has right now could make him a #2 starter, or does he not have that particular potential, in which case he'll likely stall? Are we only seeing 2/3 of what Mazzaro's arsenal will be as a 24 year old starter, or is he stuck trying to make it with a good fastball, decent slider, and "show me" changeup? Will Cunningham take his excellent swing and minor league numbers to match, and converge them at the big league level due to one of Jim Skaaaaaaalan's famous "timing devices," or will Mark McGwire get to him first and Cunningham won't hit .474 until he joins the Cardinals? My question for this discussion is: When trying to project a player's future, how do you factor in the additions and changes they might be able to make? Not everyone can learn how to add and subtract on the fastball, or can adjust their hands to suddenly stay back better on offspeed pitches, no matter how good the tutelage may be. Yet a player with poor results now may be a star in the making, if you just imagine the changes they are capable of making between now and when you want to count on them to be good. I didn't see it coming with Braden, but maybe I should have. Maybe I should have seen a guy with the perfect competitive makeup, excellent fastball command, the intelligence and resolve to learn new things, and realized that he would, and could, learn whatever he needed to learn to get a lot better. What should I see about Trevor Cahill, Vin Mazzaro, Aaron Cunningham, Gio Gonzalez, Tommy Everidge, Cliff Pennington, that I can't see now because it hasn't actually happened yet?