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. | Joss, Addie | (filler8) | Kentucky Horses | 30 |
| 2. | McLain, Denny | (dynasty) | Pittsburgh Plunder | 30 |
| 3. | Koufax, Sandy | (dynasty) | Pittsburgh Plunder | 29 |
| 4. | Tesreau, Jeff | (filler8) | Seattle Sloths | 29 |
| 5. | Hamels, Cole | (walle-1) | Louisiana Gators | 29 |
| 6. | Plesac, Zach | (hanson) | Oconee Riverdawgs | 29 |
| 7. | Sabathia, CC | (dom1134157) | Florida Gators | 29 |
| 8. | McGinnity, Joe | (Ask12be1) | Bronx Hitmen | 29 |
| 9. | Andujar, Joaquin | (dynasty8) | Utah Nightmares | 29 |
| 10. | Drysdale, Don | (filler8) | Iowa Pigs | 29 |
| 11. | Sutton, Don | (walle-1) | Louisiana Gators | 29 |
| 12. | Pfiester, Jack | (filler8) | Portland Vikings | 28 |
| 13. | Vander Meer, Johnny | (walle-1) | Portland Vikings | 28 |
| 14. | Hendrix, Claude | (TheVinci) | Sacramento Lions | 28 |
| 15. | Pfiester, Jack | (TheVinci) | Sacramento Lions | 28 |
| 16. | Newcombe, Don | Florida Crabs | 28 | |
| 17. | Cicotte, Eddie | Burnham Big Blues | 28 | |
| 18. | Cicotte, Eddie | (dynasty) | Utah Nightmares | 28 |
| 19. | Tanana, Frank | (sthompson77566) | Texas Tigers | 28 |
| 20. | Halladay, Roy | (rlapierre) | MAINE BLACK BEARS | 28 |
| 21. | Taylor, Jack | (WorcWarr) | Worcester Warriors | 28 |
| 22. | Lyons, Ted | (dynasty8) | Iowa Pigs | 28 |
| 23. | Bender, Chief | (richp) | Beantown Bombers | 28 |
| 24. | Sutton, Don | (Klose_Call) | Burnham Old Athletics | 28 |
| 25. | Shields, James | (dynasty) | Arizona Suns | 28 |
| 26. | Swindell, Greg | (jeffky1229) | Louisville Union | 28 |
| 27. | Chance, Dean | (walle-1) | Boston Bees | 28 |
| 28. | White, Doc | (dynasty8) | Pittsburgh Plunder | 28 |
| 29. | McLain, Denny | NASHVILLE NIGHT RIDERS | 28 | |
| 30. | Joss, Addie | (JohnHeidy) | Highland Hi-Ballers | 28 |
| 31. | Reulbach, Ed | Pittsburgh Plunder | 28 | |
| 32. | Viola, Frank | (dynasty) | Chicago Reapers | 28 |
| 33. | Saberhagen, Bret | (dynasty) | Charlotte Spiders | 28 |
| 34. | White, Doc | (walle-1) | Atlanta Gorillas | 28 |
| 35. | McGinnity, Joe | (dynasty) | Nevada Snakes | 28 |
| 36. | Drysdale, Don | (dynasty8) | Utah Nightmares | 28 |
| 37. | Wood, Joe | Tucson Dirt Devils | 28 | |
| 38. | Ford, Whitey | (filler8) | Nevada Snakes | 28 |
| 39. | Blyleven, Bert | (TheVinci) | Kentucky Horses | 28 |
| 40. | Chesbro, Jack | (sheikyerboudi) | Dog Breath in the YearOfThePlague | 28 |
| 41. | Sweeney, Charlie | (dynasty) | Portland Vikings | 28 |
| 42. | Krukow, Mike | (dynasty) | Iowa Pigs | 28 |
| 43. | Kluber, Corey | (dynasty) | Pittsburgh Plunder | 27 |
| 44. | Krock, Gus | (dynasty8) | Las Vegas Gladiators | 27 |
| 45. | Tudor, John | (filler) | Iowa Pigs | 27 |
| 46. | Young, Cy | Pete Rose Gamblers | 27 | |
| 47. | Young, Cy | (walle-1) | Toronto Tigers | 27 |
| 48. | Ferguson, Charlie | (wisely1300) | Milwaukee Bats | 27 |
| 49. | Mathewson, Christy | (wisely1300) | Milwaukee Bats | 27 |
| 50. | Marichal, Juan | (walle-1) | Toronto Tigers | 27 |
