80 - Hall of Fame Caliber Among the best ever. Should be getting out very, very sparingly. Miguel Cabrera's hitting; Giancarlo Stanton's power.
70 Perennial All-Star Well above-average ability in a particular area. Matt Harvey's fastball; Mike Trout's speed.
60 - All-Star Caliber Solidly above average.
55 - One Grade Above Average Overall production will consistently meet or exceed the league average for his position, or have a particular skill that is one tick above the league average.
50 - Solid-Average Player at the Major League Level For an overall grade, this represents a position player who will play every day in the majors, a starting pitcher in the third or fourth slots in a major league rotation, or an average middle reliever or setup man. For an individual attribute, this represents a league-average skill (a .270 batting average, a 90 mph fastball).
45 - Below-Average-Player Either a starter on a second-division club, or a bench player on an average or better club. Would include fourth outfielders, fifth/sixth starters, 11th/12th men on a pitching staff, etc.
40 - Future Potential Player An outside chance to get a "cup of coffee." Well below-average ability.
35 - Non-Prospects Will top out at, or likely before reaching, Double-A.
30 - Not a Pro Player A skill level just one tick above the worst possible grade.
20 - Lowest Player Grade Frank Thomas' running speed; Juan Pierre's power; Steve Blass' control.