Favorite Teams leagues are not included in Single-Season records. Records only remain for 10 seasons.
Single-Season Leaders (ERA)
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. | Rivera, Mariano | (Trilling) | LA Tanks | 0.25 |
| 2. | Adams, Mike | (RichieBlondet) | West Side Whizzers | 0.27 |
| 3. | Jansen, Kenley | (filler8) | Phoenix Dragons | 0.28 |
| 4. | Benitez, Armando | (filler) | Kansas Grasshoppers | 0.52 |
| 5. | Schiraldi, Calvin | (filler8) | Florida Crabs | 0.57 |
| 6. | Jackson, Mike | (filler) | Miami Serpents | 0.57 |
| 7. | Nathan, Joe | (Mortamar1966) | Morleyville Mud Skippers | 0.58 |
| 8. | Eichhorn, Mark | (chaaad) | BX Bombers | 0.59 |
| 9. | Rivera, Mariano | (dynasty) | Montana Ducks | 0.60 |
| 10. | Adams, Mike | (nycubsfan) | Jackson Heights Knights | 0.63 |
| 11. | Uehara, Koji | (Babadude88) | Morgantown Miners | 0.63 |
| 12. | McGraw, Tug | Louisiana Gators | 0.64 | |
| 13. | Jansen, Kenley | (jeffery2323) | Barton Barmaids | 0.65 |
| 14. | Chapman, Aroldis | (NICKACHAP) | Folcroft Falcons | 0.65 |
| 15. | Doolittle, Sean | (sgt714) | Boston Red Sox | 0.67 |
| 16. | Papelbon, Jonathan | (ThEiRoNhOrSe04) | Liberty Banditos 57 | 0.68 |
| 17. | Abernathy, Ted | (walle-1) | Sacramento Lions | 0.68 |
| 18. | Street, Huston | (RichGibson) | IWW PYRAMIDS | 0.68 |
| 19. | Street, Huston | (nycubsfan) | Goshen Gorillas | 0.69 |
| 20. | Davis, Wade | (filler8) | Iowa Pigs | 0.69 |
| 21. | Adams, Mike | 12th Man Leftovers | 0.71 | |
| 22. | Alvarado, Jose | Denver Eagles | 0.71 | |
| 23. | Chapman, Aroldis | (richgibson) | US CANNONFODDER | 0.72 |
| 24. | Eckersley, Dennis | (richgibson) | Boys Who Said Sir No Sir | 0.72 |
| 25. | Feliz, Neftali | (richgibson) | LIVING MUMMIES | 0.73 |
| 26. | Howe, Steve | (filler) | Carolina Bulldogs | 0.72 |
| 27. | Wilhelm, Hoyt | (filler) | Denver Eagles | 0.73 |
| 28. | Eckersley, Dennis | (Trulaia) | Vermont Lake Monsters | 0.73 |
| 29. | Uehara, Koji | (jrobandsteal) | NASHVILLE NIGHT RIDERS | 0.74 |
| 30. | Belinda, Stan | (Trulaia) | staten island ironworkers | 0.74 |
| 31. | Broxton, Jonathan | (brian4656) | Florida Crabs | 0.75 |
| 32. | Hall, Dick | Montana Ducks | 0.75 | |
| 33. | Benitez, Armando | (Mvos18) | Stone Temple Foo Peppers | 0.75 |
| 34. | Uehara, Koji | (Artinshki) | Base Ball Classics | 0.75 |
| 35. | Doolittle, Sean | (JDfrost) | Greenville All Stars | 0.76 |
| 36. | Iglesias, Raisel | (walle-1) | Portland Vikings | 0.76 |
| 37. | Harris, Will | (Jeter0296) | Staten Island Yankees | 0.77 |
| 38. | Montgomery, Jeff | (johnmardis) | Warner Town Animaniacs | 0.78 |
| 39. | Papelbon, Jonathan | (RichieBlondet) | Brooklyn Boppers | 0.78 |
| 40. | Adams, Mike | (chaaad) | LIU Sharks | 0.78 |
| 41. | Diaz, Carlos | (jeter0296) | Freehold Knights | 0.79 |
| 42. | Harden, Rich | (Jrobandsteal) | Denver Eagles | 0.80 |
| 43. | Gagne, Eric | (richp) | Bay City Bombers | 0.81 |
| 44. | Holland, Greg | (michelb3514) | Iowa Corn Pickers | 0.81 |
| 45. | Eichhorn, Mark | (johnmardis) | Warner Town Animaniacs | 0.81 |
| 46. | Uehara, Koji | (filler) | Milwaukee Skeletons | 0.81 |
| 47. | Zimmerman, Jeff | (rlapierre) | Long Island Express | 0.82 |
| 48. | Fromme, Art | (walle-1) | Carolina Bulldogs | 0.82 |
| 49. | Capps, Carter | (chaaad) | Bartons Nighthawks | 0.81 |
| 50. | Melancon, Mark | (Trulaia) | Chapecó Panther | 0.82 |
