Of those 15, the guys who were in the majors at 21 are: Peralta: who was terrible over a half season, had one great season before this year. Beltran: who had a cup of coffee with similar numbers to Castro when adjusting for the sillyball era, and didn't become CARLOS BELTRAN until his age 24 season Reyes: Who was terrible in a half season following a half season at age 20 that was slightly better than Castro's. Is having his best season by far at age 28. McCann: Who was slightly worse than Castro, followed by a huge year at 22, back to his age 21 levels at 23, before settling in as an all-star at 24. Ortiz: Who was similar in a cup of coffee, improved in the next year's half season, missed time to injury, bounced around the same #s until he found the needle in Boston at age 27. Upton: Took a big leap in his age 21 season after debuting at 19. Regressed some at 22, busted out bigger this year at 23. Upton's the only one who was clearly ahead of Castro's career arc at the time, with a few of these guys having similar slash lines with a little in my-head run environment adjustment (i.e. low walks, middling power) Eyeballing those 15, how many do you think would be projected for a better career arc than Castro through their age 21 seasons (strictly hitting)? Upton, Tex, Gordon, and Helton is all I'm seeing off the top of my head.