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. | McLain, Denny | (filler8) | Kentucky Horses | 30 |
| 2. | Joss, Addie | (filler8) | Montana Ducks | 30 |
| 3. | Hamels, Cole | (filler) | Kentucky Horses | 29 |
| 4. | McGinnity, Joe | (filler8) | Milwaukee Skeletons | 29 |
| 5. | Plesac, Zach | Boulder Cavemen | 29 | |
| 6. | Sutton, Don | (dynasty) | Denver Eagles | 29 |
| 7. | Koufax, Sandy | (filler8) | Kentucky Horses | 29 |
| 8. | Sabathia, CC | (walle-2) | Iowa Pigs | 29 |
| 9. | Andujar, Joaquin | (walle-1) | San Diego Sharks | 29 |
| 10. | Drysdale, Don | (dynasty) | Kentucky Horses | 29 |
| 11. | Tesreau, Jeff | (filler8) | Carolina Bulldogs | 29 |
| 12. | Cicotte, Eddie | (cubsarethebest) | South Bend Cubs | 28 |
| 13. | Cicotte, Eddie | (dynasty) | Utah Nightmares | 28 |
| 14. | Krukow, Mike | (dynasty) | Atlanta Gorillas | 28 |
| 15. | Taylor, Jack | (WorcWarr) | Worcester Warriors | 28 |
| 16. | Halladay, Roy | (godelfan) | Beaverdale Borg | 28 |
| 17. | Hendrix, Claude | (sheikyerboudi) | Burnt Weeny Sandwich | 28 |
| 18. | Pfiester, Jack | (sheikyerboudi) | Burnt Weeny Sandwich | 28 |
| 19. | Sweeney, Charlie | (dynasty) | Kentucky Horses | 28 |
| 20. | White, Doc | (CoachHollett) | Atlanta Gorillas | 28 |
| 21. | McGinnity, Joe | (filler) | Louisiana Gators | 28 |
| 22. | Blyleven, Bert | (Rainman) | Salem Demons | 28 |
| 23. | Viola, Frank | (Andymancan) | Iowa Pigs | 28 |
| 24. | Drysdale, Don | (dynasty) | Nevada Snakes | 28 |
| 25. | Chesbro, Jack | (sheikyerboudi) | Dog Breath in the YearOfThePlague | 28 |
| 26. | Bender, Chief | (richp) | Beantown Bombers | 28 |
| 27. | Ford, Whitey | (todorojo) | Spanish Fork Toros | 28 |
| 28. | Pfiester, Jack | Denver Eagles | 28 | |
| 29. | White, Doc | (walle-1) | Miami Serpents | 28 |
| 30. | Newcombe, Don | (walle-1) | Texas Outlaws | 28 |
| 31. | McLain, Denny | (jrobandsteal) | NASHVILLE NIGHT RIDERS | 28 |
| 32. | Tanana, Frank | Atlanta Gorillas | 28 | |
| 33. | Saberhagen, Bret | (filler8) | Nevada Snakes | 28 |
| 34. | Lyons, Ted | (dynasty) | Charlotte Spiders | 28 |
| 35. | Reulbach, Ed | (sheikyerboudi) | Schlitz Brewmeisters | 28 |
| 36. | Wood, Joe | (L2P) | Tucson Dirt Devils | 28 |
| 37. | Sutton, Don | (AR00) | Beartooth Blizzard | 28 |
| 38. | Shields, James | (dynasty8) | Kentucky Horses | 28 |
| 39. | Swindell, Greg | (lifeindecember) | Uncanny X-Men | 28 |
| 40. | Chance, Dean | (CoachHollett) | Boston Bees | 28 |
| 41. | Vander Meer, Johnny | (dynasty) | Las Vegas Gladiators | 28 |
| 42. | Joss, Addie | (JohnHeidy) | Highland Hi-Ballers | 28 |
| 43. | Marquez, German | (rennies) | Miami Vipers | 27 |
| 44. | Chesbro, Jack | (dynasty) | Dallas Mustangs | 27 |
| 45. | Hunter, Catfish | (AR00) | Sideshow Bobs | 27 |
| 46. | Sale, Chris | (AR00) | Sideshow Bobs | 27 |
| 47. | Smithson, Mike | (walle-1) | Seattle Sloths | 27 |
| 48. | Tyler, Lefty | (dynasty8) | Montana Ducks | 27 |
| 49. | Johnson, Si | (kycatzrock) | Lebanon Ridge Runners | 27 |
| 50. | Young, Cy | (godelfan) | Wasilla Spektors | 27 |
