Every team and every person has a different philosophy about how their team should approach the draft, and to be honest there is no right answer. I’ve always preferred high school players because the sooner you get them into a professional system with professional instruction and conditioning programs, the better. College programs have come a long way, but those coaches can still do lots of damage (especially to pitchers). Oh sure, you’ll have to wait longer for your prize when drafting high schoolers, but that’s life.
In a piece for THT, Alex Pedicini looked at the top 100 draft picks from 1992-1999, and determined the most valuable demographics in terms of WAR. College hitters in the first round are generally the safest group, averaging 1.336 WAR per year during their first six seasons in the bigs (which their original team controls), while college pitchers are the most dangerous at just 0.649 WAR/year. That’s right, taking a high school pitcher in the first round has historically been a safer pick that their college counterparts.
Pedicini also breaks it down by draft pick (the top 20 picks are by far the most valuable) and position (corner infielders and outfielders are the safest, righty pitchers by far the riskiest). Check it out, it’s a short but very interesting read.