Most baseball fans like to look at minor league pitching stats and dream about what a player might become. We look at the teenager who blows away A ball hitters and wonder if he might be the next Dwight Gooden. At the same time, we haven't seen most of these pitchers pitch regularly (if at all) and we must rely on scouts for anecdotal information. The one thing we do have is a confusing tangle of numbers. But what, if anything, do they indicate about a pitcher's likelihood of making it in the majors?
The following performance ratings are based on the pitcher's performance relative to minor league level and age, and are adjusted for league and for whether the pitcher was a starter or a reliever in the minors. Major league stats are NOT included in the evaluation.
About 70% of the core performance rating (before adjustments) is comprised of strikeout and walk rates per opportunity. The rest of the core rating is comprised of homeruns allowed rates and hits allowed per ball in play. The method takes a "wait-and-see" approach with pitchers in the lower minors - it recognizes that these pitchers face two sets of hurdles before reaching the majors: (a) the need to polish their arsenal to get more experienced hitters out; and (b) avoiding injuries. It's very difficult for a college pitcher pitching in low-A ball to compile a high rating. Most college pitchers' ratings improve in their first full year.
The informal letter grading system used by John Sickels and others roughly corresponds to the following rating scale (which I will call "prospect rating" for lack of a better term):
105 plus : A+
95-105 : A
90 -95 : A-
85-90 : B+
75-85 : B
72-75 : B-
69-72 : C+
63-69 : C
60-63 : C-
In the following chart, pitchers 26 and older as of July 1, 2003 and pitchers with less than 200 Batters Faced in 2003 are excluded.
Blue Jays minor league pitchers:
Pitcher .............. PA Rating Letter Grade
Dustin McGowan ..... 637 92.0 A-
David Bush ......... 643 89.2 B+
Corey Thurman ...... 373 86.3 B+
Jason Arnold ........ 659 83.4 B
Vinny Chulk ......... 524 81.9 B
Jamie Vermilyea ..... 205 80.0 B
Vince Perkins ........ 519 78.6 B
Jesse Harper ........ 531 76.5 B
Joshua Banks ........ 264 76.0 B
Gustavo Chacin ...... 314 75.9 B
Dave Gassner ......... 608 75.9 B
Josh Towers .......... 545 73.5 B-
Brandon League ....... 573 73.4 B-
Cameron Reimers ...... 684 73.1 B-
Derrick Nunley ....... 246 73.0 B-
Chris Baker .......... 660 72.1 B-
Pitcher ...... Organisation Rating PA
Harden, Rich ....... OAK ... 115.7 396
Soriano, Rafael .... SEA ... 113.2 241
Tsao, Chin-hui ..... COL ... 111.8 446
Jackson, Edwin ..... LAD ... 111.2 619
Perez, Oliver ...... SDP ... 110.5 200
Balfour, Grant ..... MIN ... 108.6 276
Cotts, Neal ........ CWS ... 106.1 440
Crain, Jesse ........ MIN ... 105.9 326
Hamels, Cole ....... PHI ... 103.5 383
Bevis, P.J. ......... NYM ... 103.3 334
Jenks, Bobby ....... ANA ... 102.6 363
Zumaya, Joel ....... DET ... 102.0 376
Blackley, Travis ... SEA ... 101.9 658
Miller, Greg ....... LAD ... 101.6 581
Cabrera, Fernando . CLE ... 100.8 456
Tankersley, Dennis . SDP ... 100.3 660
Vogelsong, Ryan .... PIT ... 100.0 643
Munoz, Arnaldo ..... CWS .... 99.8 238
Riley, Matt ........ BAL .... 99.5 597
Madson, Ryan ....... PHI .... 99.0 694
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