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. | Pascual, Camilo | (dynasty) | Florida Panthers | 33 |
| 2. | Loaiza, Esteban | (LimitedSwish) | Saskatchewan Bootleggers | 32 |
| 3. | Milton, Eric | (Bucky) | Erie Fighters | 31 |
| 4. | Chance, Dean | (Searcy) | Oklahoma Barons | 31 |
| 5. | Leake, Mike | (steveh28) | Reno Rhino s | 31 |
| 6. | Hernandez, Felix | (Artinshki) | Portland Bounty | 31 |
| 7. | Bunker, Wally | (dynasty) | Florida Panthers | 31 |
| 8. | Yarbrough, Ryan | (HaloFire) | Tottenville Pirates | 30 |
| 9. | Ryan, Nolan | (coachmcs) | Erie Fighters | 30 |
| 10. | Foreman, Frank | (akylos) | Long Beach Sharks | 30 |
| 11. | Benes, Andy | (tbsmit) | San Bernardino Livewires | 30 |
| 12. | Neagle, Denny | (Bears19) | Erie Fighters | 30 |
| 13. | Kile, Darryl | (LDJS1947) | FLORIDA LOBSTERS | 29 |
| 14. | Pettitte, Andy | (ressien) | Washington Huskies | 29 |
| 15. | Waddell, Rube | (BeeDotJayDot) | Erie Fighters | 29 |
| 16. | Valenzuela, Fernando | (JStrauss51) | Hyde Park Maroons | 29 |
| 17. | Hahn, Noodles | (BigPaws) | Philadelphia ATHLETICS | 29 |
| 18. | Milone, Tom | (jcbsavages) | Mudville Demons | 29 |
| 19. | Powell, Jack | (nbb412) | Washington Senators | 29 |
| 20. | Young, Irv | (pdawg) | Brooklyn Bums | 29 |
| 21. | Carpenter, Chris | (sidbuddha) | DC Clusters | 29 |
| 22. | Jenkins, Fergie | (kinghank) | Central PA Sweathogs | 29 |
| 23. | Hernandez, Felix | (jjfid66) | Boston LIBERATORS | 29 |
| 24. | Morris, Jack | (metfan1) | Bartonsville Pumas | 29 |
| 25. | Clemens, Roger | (WorcWarr) | Worcester Warriors | 29 |
| 26. | Feller, Bob | (tgbsbl1967) | Canton Studs | 29 |
| 27. | Young, Chris | (Potholes) | Grover Potholes | 29 |
| 28. | Young, Irv | (Berg) | St. Louis Eagles | 28 |
| 29. | Greinke, Zack | (WeatherOK) | D.C. Deep Swamp | 28 |
| 30. | Scott, Mike | (fps1956) | Stinky Bums | 28 |
| 31. | Powell, Jack | (Rjhinsley) | Chicago Logan Squares | 28 |
| 32. | Blyleven, Bert | (Bobveale39) | Miami Cats | 28 |
| 33. | Maddux, Greg | (dynasty) | Houston Colt .45's | 28 |
| 34. | Morris, Ed | (SoggyBiscuit) | Gas City Green Sox | 28 |
| 35. | Newhouser, Hal | (sstack04) | Battle Creek Idiots | 28 |
| 36. | Powell, Jack | (sammy-z) | Candy Land Peppermints | 28 |
| 37. | Powell, Jack | (frankieone) | Hollywood T- Birds | 28 |
| 38. | Bender, Chief | (mattholland1975) | Norwich Ninjas | 28 |
| 39. | Hurst, Bruce | (Arcticwolf) | Rock Tavern Shop Stewards | 28 |
| 40. | Ford, Whitey | (leefoyt) | Chumpville Canners | 28 |
| 41. | Lima, Jose | (AxEl_R) | New York Highlanders | 28 |
| 42. | Nagy, Charles | (AxEl_R) | New York Highlanders | 28 |
| 43. | Blyleven, Bert | (ManuForti88) | Elmhurst Allstars | 28 |
| 44. | Phillippe, Deacon | (jtgagne9) | Punta Cana Toro's | 28 |
| 45. | McLain, Denny | (dzach) | Husavik Jaja Ding Dongs | 28 |
| 46. | Perez, Melido | (doceagle) | Frederick Keys | 28 |
| 47. | Dinneen, Bill | Good Old Chillidogs | 28 | |
| 48. | Lonborg, Jim | (Gibblets1973) | Los Gibbletos 18ighteen | 28 |
| 49. | Blyleven, Bert | (Smally08) | Castle Rock Rockets | 28 |
| 50. | Gura, Larry | (filler) | Oklahoma Mullets | 28 |