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 | Wild Cats | 33 | |
| 2. | DeSclafani, Anthony | (JustinTime420) | Boston Bees | 33 |
| 3. | Cain, Matt | (Haydenlewis10) | DubV Sharks | 32 |
| 4. | Smith, Caleb | (JustinTime420) | Boston Bees | 31 |
| 5. | Williams, Lefty | Wild Cats | 31 | |
| 6. | Stieb, Dave | (ikej) | Maine Natives | 30 |
| 7. | McLain, Denny | (dunroche) | Chenango Wolves | 30 |
| 8. | Sutton, Don | (filler8) | Saskatchewan Macho Mallards | 30 |
| 9. | Koufax, Sandy | (dunroche) | Chenango Wolves | 29 |
| 10. | Tudor, John | (dynasty) | Canarsie Cannibals | 29 |
| 11. | Hunter, Catfish | (filler2) | Dark Avengers | 29 |
| 12. | McGinnity, Joe | (dynasty8) | Treasure Island ROBBERS | 29 |
| 13. | Hershiser, Orel | (Bravesman) | Shreveport Sharks | 29 |
| 14. | Chesbro, Jack | (BobbyCarnes) | RED Sergeants | 29 |
| 15. | Koufax, Sandy | (filler) | Povoação Povoação Hitmen | 29 |
| 16. | Drysdale, Don | (filler) | Avondale Poo Flingers | 29 |
| 17. | Sweeney, Charlie | (mdsyverson) | Saskatchewan Saskatoons | 28 |
| 18. | White, Doc | (filler) | Funky Balls Deep | 28 |
| 19. | Hendrix, Claude | (filler8) | Seattle Pilots | 28 |
| 20. | Pfiester, Jack | (filler8) | Seattle Pilots | 28 |
| 21. | Higuera, Teddy | (bnewman58) | Havana Nightmare | 28 |
| 22. | Newcombe, Don | (filler) | Chicago Cougars | 28 |
| 23. | White, Doc | (filler) | Chicago Logan Squares | 28 |
| 24. | Tanana, Frank | (filler) | Kenmare Kestrels | 28 |
| 25. | Sutton, Don | (dynasty) | Eagle Claws | 28 |
| 26. | Dobson, Pat | (filler8) | Boston Red Sox | 28 |
| 27. | Voth, Austin | (JustinTime420) | Boston Bees | 28 |
| 28. | Moyer, Jamie | (acr0320) | Traverse City Beach Bums | 28 |
| 29. | Shields, James | (whtsittou83) | Schvitz Sweatmen | 28 |
| 30. | Perez, Pascual | (JTExpress) | Raleigh Oaks | 28 |
| 31. | Pfiester, Jack | (idesofmarch) | Chisholm Trail Drovers | 28 |
| 32. | Coombs, Jack | (dynasty) | Flint City Spartans | 28 |
| 33. | Hunter, Catfish | MALIBU SURFERS | 28 | |
| 34. | McLain, Denny | (dunroche) | Tuvalu Copras | 28 |
| 35. | Cicotte, Eddie | (filler) | Nakatomi Die Hards | 28 |
| 36. | Blyleven, Bert | (filler8) | Owlezvous Francais | 28 |
| 37. | Harper, Jack | (filler) | Memphis Pharoahs | 28 |
| 38. | Altrock, Nick | (sheikyerboudi) | Feral Groundhogs | 28 |
| 39. | Bender, Chief | (filler8) | Hitless Wonders | 28 |
| 40. | Saberhagen, Bret | (kurnal_sanders4) | Chenango Wolves | 28 |
| 41. | White, Doc | (dynasty) | Erie Fighters | 27 |
| 42. | Rixey, Eppa | (filler8) | Jackson Oldtimers | 27 |
| 43. | Downing, Al | (Kaline65) | Tioga Tigers | 27 |
| 44. | Vaughn, Hippo | (dynasty) | Pittsburgh Pirates | 27 |
| 45. | Tannehill, Jesse | (filler) | Leo Lions | 27 |
| 46. | Wiltse, Hooks | (filler8) | Ziegfeld Follies | 27 |
| 47. | Tudor, John | (filler) | Boston Blue Sox | 27 |
| 48. | Chesbro, Jack | (redman711) | Syracuse Crusaders | 27 |
| 49. | McQuillan, George | (filler) | Three Rivers Tigers | 27 |
| 50. | Penny, Brad | (RichieBlondet) | Connecticut Mantis | 27 |