First is I don't make it harder than it should be by overthinking it. I use the 2-8 scale, 5 is average ability. So when you set the game to evaluate based on AAA the 5 is based on that. Look at AAA and AA players and see who has average, just below, or above average skills. Move onto evaluating based on AA, look at AA and HA players. Rinse and repeat.
When looking at batters I find a 4 can hit while a 3, for me, is pretty much a "no-go". This, too me, translates fairly well to all skills be it batter or pitcher. 3 stuff is probably getting blasted while a P may be able to survive with a 4. As you're thinking about all of this know the scout may be wrong and the stats may be the best indicator. Conversely the guy may be putting up stats way above his scouted skills but, he's just in a "lucky" streak and the scouted skills are what he actually is.
You then need to look at all three of the big skills (con\pow\eye, stuff, movement, control), along with stats, and determine for yourself if you think they can move up. When looking at stats also consider sample size IE how many PA, IP, etc. You then may want to consider pro years and age. Sometimes I push a guy up because it's time to "sink or swim". All the while keeping in mind the player's potential and where you see him topping out in your organization. Some guys are never leaving AA no matter what and are going to end up "aging out" and being released. That's baseball.
Batters I tend to look at WRC+ and OPS + as an "attention getter" and then drill down into the stats, sample size, age, pro years.
Pitchers.. SIERA, FIP-, ERA+ draw my eye. Then like batters I take a closer look at stats, sample size, age, pro years.
Use your imagination, think about "how would I do this IRL?", and you'll soon come up with your own system and criteria that make your MiLB evaluations go smoothly and quickly. Sometimes you'll be right. Other times you'll be wrong.
