Favorite Teams leagues are not included in Single-Season records. Records only remain for 10 seasons.
Single-Season Leaders (H/9)
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. | Adams, Mike | (BAR23) | Bucheon Everglow | 2.3 |
| 2. | Chapman, Aroldis | (Artinshki) | Base Ball Classics | 2.7 |
| 3. | Chapman, Aroldis | (rowdy1982) | Boston Sonsofbeaches | 2.9 |
| 4. | Hader, Josh | (Snowman33) | Sun City Islanders | 3.0 |
| 5. | Benitez, Armando | (wduncan) | Philadelphia Phillies | 2.9 |
| 6. | Williams, Devin | (joemcg) | OC Panthers | 3.0 |
| 7. | Chapman, Aroldis | (bnewman58) | Macon Friends | 3.0 |
| 8. | Betances, Dellin | (Wileydog97) | Raleigh Stallions | 3.0 |
| 9. | Henry, Doug | (Artinshki) | Nineties Nubbers | 3.0 |
| 10. | Chapman, Aroldis | (chaaad) | New York Bluebirds | 3.1 |
| 11. | Gagne, Eric | (bdavids28) | Silver Jet | 3.1 |
| 12. | Benitez, Armando | (757Moose) | Back in the day Brawlers | 3.1 |
| 13. | Williamson, Scott | (HouAstros1986) | Hawaii Eruptions | 3.2 |
| 14. | Marmol, Carlos | (Caphowdy504) | Springfield Troy McClures | 3.1 |
| 15. | Chapman, Aroldis | (chaaad) | Hello Kitty | 3.2 |
| 16. | Kuo, Hong-Chih | (bdavids28) | Bail Out | 3.2 |
| 17. | Marmol, Carlos | (wduncan) | Hollywood Stars | 3.2 |
| 18. | Adams, Mike | (Artinshki) | Base Ball Classics | 3.2 |
| 19. | Adams, Mike | (Trulaia) | Raleigh Angry Ducks | 3.2 |
| 20. | Kimbrel, Craig | (vonveezil) | PERRYVILLE Americans | 3.2 |
| 21. | Chapman, Aroldis | (Artinshki) | Base Ball Classics | 3.2 |
| 22. | Hader, Josh | (ThEiRoNhOrSe04) | Hoboken Zephyrs | 3.2 |
| 23. | Rivera, Mariano | (filler) | New York Pandas | 3.2 |
| 24. | Jansen, Kenley | (govols1975) | The Masked Marauders | 3.2 |
| 25. | Betances, Dellin | (stingrayjay520) | Balco Roid Rage | 3.2 |
| 26. | Hader, Josh | (sthompson77566) | Texas Sharks | 3.3 |
| 27. | Chapman, Aroldis | (chaaad) | Queens Baseball Club | 3.2 |
| 28. | Chapman, Aroldis | (Artinshki) | Base Ball Classics | 3.3 |
| 29. | Chapman, Aroldis | (bdavids28) | In Fair Light | 3.2 |
| 30. | Hader, Josh | (Artinshki) | Base Ball Classics | 3.3 |
| 31. | Saito, Takashi | (montanajack) | Washington Huskies | 3.3 |
| 32. | Chapman, Aroldis | (Artinshki) | Base Ball Classics | 3.3 |
| 33. | Chapman, Aroldis | (nycubsfan) | Htown Skeeters | 3.3 |
| 34. | Chapman, Aroldis | (dunroche) | Washington Racin' Rebels | 3.3 |
| 35. | Betances, Dellin | (richgibson) | Castaway SPEEDWELLS | 3.3 |
| 36. | Wagner, Billy | (Ruthbonds) | Saint Johns Tigers | 3.3 |
| 37. | Street, Huston | (filler) | The Good The Bat And the Utley | 3.3 |
| 38. | Soria, Joakim | (Roots) | El paso Predators | 3.3 |
| 39. | Adams, Mike | (richgibson) | San Diego SOVIETS | 3.3 |
| 40. | Boxberger, Brad | (idesofmarch) | Crieff Highlanders | 3.3 |
| 41. | Chapman, Aroldis | (chaaad) | New York Mutuals | 3.3 |
| 42. | Adams, Mike | (bostontex24) | Boston Commons | 3.3 |
| 43. | Marmol, Carlos | (filler8) | St Louis Spiders | 3.3 |
| 44. | Feliz, Neftali | (nycubsfan) | Huntsville Bearkats | 3.3 |
| 45. | Boxberger, Brad | (Tjm) | California WildFire | 3.3 |
| 46. | Adams, Mike | (tgbsbl1967) | Minot Minotaurs | 3.3 |
| 47. | Street, Huston | (bnewman58) | Macon History | 3.3 |
| 48. | Ottavino, Adam | (Alcoholic) | Jean Ralphios | 3.3 |
| 49. | Kimbrel, Craig | (dynasty8) | All-Valley Buzz | 3.3 |
| 50. | Kimbrel, Craig | (nycubsfan) | NYC Cubbies | 3.4 |
