Favorite Teams leagues are not included in Single-Season records. Records only remain for 10 seasons.
Single-Season Leaders (SO/9)
| 1. | Kimbrel, Craig | (cmm2003) | Newark Bears | 15.2 |
| 2. | Kimbrel, Craig | (malael) | New York Highlanders | 15.0 |
| 3. | Knebel, Corey | (doittoitlars) | Arizona Mustangs | 14.9 |
| 4. | Lidge, Brad | (timyoung) | Kansas City Monarchs | 14.8 |
| 5. | Uehara, Koji | (tsnets) | Boro Jokers | 14.5 |
| 6. | Kimbrel, Craig | (ThePort24) | Cresco Clashers | 14.4 |
| 7. | Hader, Josh | (bjs2025) | Altoona Rail Kings | 14.3 |
| 8. | Betances, Dellin | (Partin0701) | Starved Rockers | 14.3 |
| 9. | Edwards, Carl | (Axlrose) | Las Vegas ASHBA's | 14.4 |
| 10. | Chapman, Aroldis | Seaside Heights Sand Travelers | 14.4 | |
| 11. | Kimbrel, Craig | (chapman) | Jokes On You Fighting Clowns | 14.3 |
| 12. | Kimbrel, Craig | Minnesota Froggers | 14.3 | |
| 13. | Hand, Brad | (joemcg) | OC Prospectors | 14.3 |
| 14. | Kimbrel, Craig | (boomba) | Albuquerque Blue Crystals | 14.2 |
| 15. | Miller, Andrew | (tda81) | Las Vegas Alcoholics | 14.2 |
| 16. | Kimbrel, Craig | (roguerouge) | Boston Terriers | 14.3 |
| 17. | Hader, Josh | (Scherermj) | Fremont Huskies | 14.2 |
| 18. | Allen, Cody | Pulteney Rebels | 14.1 | |
| 19. | Kimbrel, Craig | (Charlie22) | DC Peeps | 14.2 |
| 20. | Robertson, David | (Warrior) | San Antonio Suns | 14.1 |
| 21. | Betances, Dellin | (brian4656) | Burger Kings | 14.2 |
| 22. | Clippard, Tyler | (ColinBoucher) | Derelict Winos | 14.1 |
| 23. | Betances, Dellin | (RyanSTL) | The Dirtynut | 14.0 |
| 24. | Knebel, Corey | (hoopdirt) | Island Coast Gators | 14.1 |
| 25. | Betances, Dellin | (hballplayer7) | Bedrock Water Buffalo | 14.2 |
| 26. | Givens, Mychal | (shermanator) | Montreal Expos | 14.1 |
| 27. | Kimbrel, Craig | (gdavis32) | Wilmington Quakers | 13.9 |
| 28. | Kimbrel, Craig | (Trulaia) | Collinsville Cobras | 13.9 |
| 29. | Betances, Dellin | (Mromito) | Baseball Baseball | 14.0 |
| 30. | Kimbrel, Craig | (joemcg) | OC Prospectors | 14.0 |
| 31. | Miller, Andrew | (Bomber23) | Thurmont Tigers | 13.9 |
| 32. | Chapman, Aroldis | (GusPC13) | Pangaea Knights | 13.9 |
| 33. | Jansen, Kenley | (Mattp598) | Bitburg Bonzos | 13.9 |
| 34. | Betances, Dellin | (dieselduro) | Havana Hurricanes | 14.0 |
| 35. | Oh, Seung-hwan | Long Island Lobsters | 14.0 | |
| 36. | Goody, Nick | (brian4656) | Nippes Swingin‘ Bats | 13.8 |
| 37. | Diaz, Edwin | (habsco) | Chicago Cub | 13.9 |
| 38. | Diaz, Edwin | (Frug) | Los Angeles Sharks | 13.8 |
| 39. | Doolittle, Sean | (Alex) | Detroit Gorillas | 13.7 |
| 40. | Betances, Dellin | Vienna Buccos | 13.7 | |
| 41. | Betances, Dellin | (alphabeta) | Anheuser-Busch Buds | 13.8 |
| 42. | Edwards, Carl | (drh4740) | Portland Frogs | 13.8 |
| 43. | O'Day, Darren | (vaughnk003) | Messick Mud Dogs | 13.8 |
| 44. | Kimbrel, Craig | (UNHBombers) | Stowe UNH Bombers | 13.8 |
| 45. | Giles, Ken | (doittoitlars) | Arizona Mustangs | 13.9 |
| 46. | Robertson, David | (BigRedMachine90) | Beating My Snake | 13.8 |
| 47. | Peacock, Brad | LJW Bolt | 13.8 | |
| 48. | Capps, Carter | (michelb3514) | Iowa Corn Pickers | 13.8 |
| 49. | Kimbrel, Craig | (baconfats) | Clubber Langs | 13.7 |
| 50. | Knebel, Corey | (jaredhamann) | Uniondale Firebirds | 13.8 |