The plate discipline problem is one the Phils don't seem to have handled that well with other recent prospects (Bohm, Stott, Rojas, etc.). I often wonder how much plate discipline is teachable to prospects. Maybe they already have a mental image of their swing zones combined with a certain amount of psychological patience and it's not going to change much.
We tend to say "stop swinging at pitches out of the zone" to guys like Castellanos and Turner, but I really suspect what you see is what you'll get with them, and maybe for pretty much all prospects, too. The ones who were patient in the minors tend to be patient in the majors, and the ones who were patient in high school and college and club ball tend to stay that way as professional prospects. Players just don't go from 30-40 OBP points due to walks to 80-100 OBP points. They seem to get 5 or 10 points as they age in total, but stay in the same range. The only exceptions I know of were steroid-era guys like Sammy Sosa whose jumps in power changed the way they were being pitched.
Crawford has put up roughly 125-130 OPS+ in 4 consecutive stops in the minors with his current approach. I'd be really reluctant to try to get him to lift the ball more and be a lot more patient. I'll take the high average hitter with 50 OBP points of walks or so (6 or 7 BB%) and 140-160 points of ISO. [300/350/450 would be fine] He should spend his time figuring out better routes in CF, which I do think is teachable with practice and experience.
