Single-A to the Majors
Which Single-A stats separate future big leaguers from everyone else, and which ones predict success once they get there.
586 pitchers · 85 reached MLB444 hitters · 68 reached MLBFlorida State League 2021–23, followed through 2026 · October 2026
Pitchers
Who reaches the majors
Score = how often the stat ranks a player who reached MLB by 2026 above one who hadn't. 50 is a coin flip.
- Pitching+75
- K-BB%72
- Top-end fastball velo72
- Stuff+69
- xwOBA against68
- K%68
- CSW%68
- Location+65
- BB% (low)64
- Age (young)58
- Fastball ride56
- Exit velo against56
- Ground-ball %54
- Breaking-ball whiff %53
- Arm angle49
Reached MLB, by Pitching+ fifth
3%
5%
14%
14%
37%
Gets you there
- Pitching+, K-BB% and top-end fastball velo
- Top-end velo and K-BB% each add something the other doesn't
- Among top-third Stuff+ arms, 9 of 21 aged 20 or younger reached, vs 17 of 109 aged 23+
Makes you good there
- Of the 85 who reached, 20 have 1+ MLB WAR. Pitching+ picks them out best (74), then K-BB% (72)
- MLB K-BB% tracks Single-A K-BB%, fastball whiffs and extension
- Single-A velo showed no link to MLB K-BB%
Hitters
Who reaches the majors
- xwOBA72
- BB% minus K%70
- Whiff per swing (low)69
- K% (low)69
- Extra-base power68
- Zone contact %66
- Avg exit velo63
- Age (young)62
- Barrel %58
- Top-end exit velo57
- Chase % (low)55
- Launch angle54
- Pulled air %50
Reached MLB, by whiff-per-swing fifth
2%
13%
9%
25%
27%
Gets you there
- Expected production (xwOBA)
- Not swinging and missing
- Being young for the level
- Raw power (barrels, top exit velo) barely separates
Makes you good there
- Of the 68 who reached, 20 have 1+ MLB WAR. Low K% (63) and youth (62) separate them only modestly
- Exit velo comes back: Single-A exit velo is the best predictor of MLB xwOBA