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. | Young, Cy | (sheikyerboudi) | Bad News Beers | 33 |
| 2. | Pascual, Camilo | Florida Panthers | 33 | |
| 3. | White, Doc | (mckarcher) | Black Mesa Xens | 33 |
| 4. | DeSclafani, Anthony | (dbacksstar) | BB Bison | 33 |
| 5. | Cain, Matt | (hanson) | Lil Rhody Have A Gansett | 32 |
| 6. | Chance, Dean | (filler8) | Olde English 800's | 31 |
| 7. | Bunker, Wally | Florida Panthers | 31 | |
| 8. | Williams, Lefty | (sheikyerboudi) | Bad News Beers | 31 |
| 9. | Milton, Eric | (whitehats) | Erie Fighters | 31 |
| 10. | Smith, Caleb | (dbacksstar) | BB Bison | 31 |
| 11. | Stieb, Dave | (ikej) | Maine Natives | 30 |
| 12. | Scherzer, Max | (mckarcher) | Black Mesa Xens | 30 |
| 13. | Yarbrough, Ryan | (dynasty) | Tottenville Pirates | 30 |
| 14. | Ryan, Nolan | (coachmcs) | Washington Champions | 30 |
| 15. | Benes, Andy | (filler) | Montreal Monarchs | 30 |
| 16. | Hunter, Catfish | (filler) | Kansas City Packers | 29 |
| 17. | Waddell, Rube | (filler8) | Woodenville Waterfowls | 29 |
| 18. | Milone, Tom | (Mav54) | Des Moines Demons | 29 |
| 19. | Powell, Jack | (sheikyerboudi) | Pabst Keggers | 29 |
| 20. | Koufax, Sandy | Janesville shocKers | 29 | |
| 21. | Kershaw, Clayton | (TheVinci) | Outback Hail Mary's | 29 |
| 22. | Marichal, Juan | (abcjz) | DALLAS ROCKETS | 29 |
| 23. | Valenzuela, Fernando | (richgibson) | Los Alamos FaT MeN | 29 |
| 24. | Young, Irv | (brian4656) | Gettysburg Cavalry | 29 |
| 25. | Dean, Dizzy | (mckarcher) | Black Mesa Xens | 29 |
| 26. | Morris, Jack | (filler8) | SOUTH BEND HELLCATS | 29 |
| 27. | Hernandez, Felix | (filler) | Serenity Now | 29 |
| 28. | Tudor, John | (dynasty) | Canarsie Cannibals | 29 |
| 29. | Ward, John | (filler) | Hartford Villans | 29 |
| 30. | Tanana, Frank | Kenmare Kestrels | 28 | |
| 31. | Voth, Austin | (dbacksstar) | BB Bison | 28 |
| 32. | Bender, Chief | (filler) | Serenity Now | 28 |
| 33. | Sale, Chris | (mckarcher) | Black Mesa Xens | 28 |
| 34. | Blyleven, Bert | (filler8) | Stillwater Cowboys | 28 |
| 35. | Powell, Jack | (filler) | 12th Man Why Nots | 28 |
| 36. | Bender, Chief | (Ruthbonds) | Norwich Ninjas | 28 |
| 37. | Powell, Jack | (dynasty) | Chicago Logan Squares | 28 |
| 38. | Valenzuela, Fernando | (dynasty) | Houston Bolts | 28 |
| 39. | Moyer, Jamie | (filler) | Traverse City Beach Bums | 28 |
| 40. | Tudor, John | (abcjz) | DALLAS ROCKETS | 28 |
| 41. | Coombs, Jack | (dynasty) | Silver City Spartans | 28 |
| 42. | Higuera, Teddy | (MikeDrop0221) | Branch County Mighty Ducks | 28 |
| 43. | Dobson, Pat | (filler) | Boston Red Sox | 28 |
| 44. | Ford, Whitey | (billyconn) | San Diego Sharks | 28 |
| 45. | McLain, Denny | (Artinshki) | Base Ball Homers | 28 |
| 46. | Greinke, Zack | (deyanksfan) | D.C. Deep Swamp | 28 |
| 47. | Young, Irv | (LDJS1947) | FREDERICKTOWN FORCE | 28 |
| 48. | Harper, Jack | (filler) | Memphis Pharoahs | 28 |
| 49. | Altrock, Nick | (sheikyerboudi) | Feral Groundhogs | 28 |
| 50. | Lima, Jose | (Theo_smith) | Columbus Bees 90's | 28 |