Favorite Teams leagues are not included in Single-Season records. Records only remain for 10 seasons.
Single-Season Leaders (Losses)
Average
OBP
SLG
OPS
At Bats
Runs
Hits
Doubles
Triples
Homers
RBIs
Walks
Strikeouts
Stolen Bases
Caught Stealing
Sac Hits
Sac Fly
HBP
GIDP
D+/-
Wins
Losses
ERA
WHIP
Innings
Hits Allowed
HR Allowed
Walks (P)
Strikeouts (p)
Complete Games
Saves
Blown Saves
Shutouts
Quality Starts
Wild Pitches
Hit Batters
H/9
BB/9
SO/9
| 1. | Loaiza, Esteban | (3FingerBrown) | Saskatchewan Bootleggers | 32 |
| 2. | Keuchel, Dallas | (jimgthomas97) | Montgomery Bashstros | 32 |
| 3. | Hernandez, Felix | Vanden Vikings | 31 | |
| 4. | Chance, Dean | (bwoodcoc) | BCS Barons | 31 |
| 5. | Milton, Eric | (PalinJames) | Erie Fighters | 31 |
| 6. | Leake, Mike | (steveh28) | Reno Rhino s | 31 |
| 7. | Yarbrough, Ryan | (BrooksBench) | Ashtabula Warriors | 30 |
| 8. | Ryan, Nolan | (PalinJames) | Erie Fighters | 30 |
| 9. | Benes, Andy | (filler) | San Bernardino Livewires | 30 |
| 10. | Cueto, Johnny | (jimgthomas97) | Montgomery Bashstros | 30 |
| 11. | Foreman, Frank | (BrooksBench) | Long Beach Sharks | 30 |
| 12. | Neagle, Denny | (PalinJames) | Erie Fighters | 30 |
| 13. | Kile, Darryl | (filler) | Florida Lobsters | 29 |
| 14. | Waddell, Rube | (ghstfcemexican) | Erie Fighters | 29 |
| 15. | Young, Chris | (dynasty) | Sault Greyhounds | 29 |
| 16. | Pettitte, Andy | (Wash56) | Webster Tigers | 29 |
| 17. | Jenkins, Fergie | (gavwag) | Biss Boosters | 29 |
| 18. | Hahn, Noodles | (Brucene18) | Philadelphia ATHLETICS | 29 |
| 19. | Higuera, Teddy | (Lare2000) | MIL MIL | 29 |
| 20. | Chandler, Spud | (Bears19) | Forest Hill-toppers | 29 |
| 21. | Carpenter, Chris | (billyconn) | Aviano Atoms | 29 |
| 22. | Powell, Jack | (nbb412) | Pittsburgh Gladiators | 29 |
| 23. | Harvey, Matt | (lasershow) | Zach Attack | 29 |
| 24. | Caldwell, Mike | (Lare2000) | MIL MIL | 29 |
| 25. | Young, Irv | (ruthbonds) | Arlington Crushers | 29 |
| 26. | Feller, Bob | (tgbsbl1967) | Canton Studs | 29 |
| 27. | Clemens, Roger | (WorcWarr) | Worcester Warriors | 29 |
| 28. | Hernandez, Felix | (jjfid66) | Boston LIBERATORS | 29 |
| 29. | Milone, Tom | (osbaseballfan) | Mudville Demons | 29 |
| 30. | Lima, Jose | (Yankees1927) | New York Highlanders | 28 |
| 31. | Nagy, Charles | (Yankees1927) | New York Highlanders | 28 |
| 32. | Scott, Mike | (fps1956) | Stinky Bums | 28 |
| 33. | Maddux, Greg | Houston Colt .45's | 28 | |
| 34. | Blyleven, Bert | (filler) | TU CHHS 200 | 28 |
| 35. | Powell, Jack | (conniemack) | Chicago Logan Squares | 28 |
| 36. | Ford, Whitey | (fatbat1318) | TU CHHS 89 | 28 |
| 37. | Kirby, Clay | (Colt45s) | Alabama Aces | 28 |
| 38. | McLain, Denny | (PalinJames) | Erie Fighters | 28 |
| 39. | Dinneen, Bill | (Joeyd8807) | Stumptown Floods | 28 |
| 40. | Bender, Chief | (jjfid66) | Boston LIBERATORS | 28 |
| 41. | Foreman, Frank | (sheikyerboudi) | Chicago Federals | 28 |
| 42. | Blyleven, Bert | (In_2_it_2) | Inland Empire 66ers | 28 |
| 43. | Gullett, Don | (Jerryp618) | CIN CIN | 28 |
| 44. | Young, Irv | (filler) | Rockford Rhinos | 28 |
| 45. | Rijo, Jose | (Jerryp618) | CIN CIN | 28 |
| 46. | Valenzuela, Fernando | (deGromination) | Springfield Atoms | 28 |
| 47. | Powell, Jack | (dynasty) | Sugarland Express | 28 |
| 48. | Tewksbury, Bob | (PalinJames) | Erie Fighters | 28 |
| 49. | Morris, Ed | (Wolfrum) | Gas City Green Sox | 28 |
| 50. | Hurst, Bruce | (Strokey) | Sand Hill Road Zoo | 28 |