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. | Britton, Zach | (leeslegends) | East County Devil Dogs | 0.00 |
| 2. | Papelbon, Jonathan | (nycubsfan) | San Antonio Texans | 0.00 |
| 3. | Broxton, Jonathan | (jericho2u) | Tropicana Tush | 0.00 |
| 4. | Street, Huston | (filler8) | Tucson Titans | 0.00 |
| 5. | Roebuck, Ed | (jpcortez) | Mid-Century Moderns | 0.16 |
| 6. | Putz, J.J. | (kingstreet) | Singapore Slingers | 0.17 |
| 7. | Putz, J.J. | (chaaad) | Schenectady Mohawk Giants | 0.19 |
| 8. | Howell, J.P. | (sgt714) | Boston Red Sox | 0.21 |
| 9. | Vande Berg, Ed | (pentucket80) | Briscoe Heights Blockheads | 0.22 |
| 10. | Lancaster, Les | (Lostit) | Chicago's Lost Cubs 1 | 0.22 |
| 11. | Shaw, Jeff | (vanderj6993) | Steroid City Roids | 0.24 |
| 12. | Boxberger, Brad | Lewisberry Old Timers | 0.25 | |
| 13. | Aardsma, David | (bush484) | Canton Lumber Company | 0.25 |
| 14. | Lincecum, Tim | (chaaad) | Kia Tigers | 0.25 |
| 15. | Chapman, Aroldis | (CornLiquor) | Jenkinstown Jameson | 0.26 |
| 16. | Britton, Zach | (Schvitz) | Pawtucket Suns | 0.26 |
| 17. | Howell, Harry | (Shpennymons) | Oyster Bay Eagles | 0.26 |
| 18. | Putz, J.J. | (paranoid) | Las Vegas Lounge Lizards | 0.26 |
| 19. | Papelbon, Jonathan | (cfreds123) | Westside Wolves | 0.27 |
| 20. | Betances, Dellin | (caustixx) | Heritage Pointers | 0.28 |
| 21. | Percival, Troy | (michelb3514) | Iowa Corn Pickers | 0.28 |
| 22. | Cooper, Mort | (dynasty) | Walsall Woodeagles | 0.29 |
| 23. | Neris, Hector | (ThEiRoNhOrSe04) | Tenn Dragons | 0.29 |
| 24. | Wagner, Billy | (filler) | New Team | 0.30 |
| 25. | Saito, Takashi | (super) | Fargo Freeze | 0.37 |
| 26. | Street, Huston | (Whg383) | Brooklyn Bisons | 0.40 |
| 27. | Cormier, Rheal | South Dakota Crooks | 0.43 | |
| 28. | Sutter, Bruce | (BamaTrashman) | ABC Eagles | 0.43 |
| 29. | Miller, Andrew | (michelb3514) | Iowa Corn Pickers | 0.46 |
| 30. | Parker, Blake | (shane211) | South Dakota Plunderers | 0.47 |
| 31. | Devine, Joey | (skooler1) | New York Highlanders | 0.47 |
| 32. | Kuo, Hong-Chih | (andyyoung) | Homestead Grays | 0.47 |
| 33. | Charlton, Norm | (itchy008) | Captain Supemarket | 0.47 |
| 34. | Chapman, Aroldis | (Sidneypointers) | Urbana Five-o | 0.47 |
| 35. | Sanders, Ken | (kingstreet) | Singapore Cowboys | 0.48 |
| 36. | Betances, Dellin | (richardcranium) | Sierra Nevada Quicksilvers | 0.48 |
| 37. | Smith, Lee | (filler) | Edmonton Mustangs | 0.48 |
| 38. | Hernandez, David | (BaltimoreChop) | Hagerstown Suns | 0.48 |
| 39. | Pagan, Emilio | (beck) | Peoria Hustlers | 0.48 |
| 40. | Papelbon, Jonathan | (filler) | Weesles Ripped My Flesh | 0.48 |
| 41. | Kuo, Hong-Chih | (Sabotage) | Chitown Sabotage | 0.49 |
| 42. | Chapman, Aroldis | (Evacu8soul) | Janesville shocKers | 0.49 |
| 43. | Miller, Andrew | (jamin) | Chester Springs Menjai | 0.49 |
| 44. | Russell, Jack | (baseball4ever) | Skull Island Kong | 0.49 |
| 45. | McGraw, Tug | (ScottCornelius) | London Yardbirds | 0.50 |
| 46. | Zimmerman, Jeff | (bostontex24) | Boston Celtics | 0.49 |
| 47. | Betancourt, Rafael | (cjay1444) | Cheyenne Cavalrymen | 0.50 |
| 48. | Hochevar, Luke | (Don55) | BB Brats | 0.50 |
| 49. | Dolis, Rafael | (GLOBEXcorp) | GLOBEX Corporation | 0.49 |
| 50. | Soriano, Rafael | (WorcWarr) | Worcester Warriors | 0.49 |