In baseball, innings pitched (IP) are the number of innings a pitcher has completed, measured by the number of batters and baserunners that are put out while the pitcher is in the game. Three outs made is equal to one inning pitched. One out counts as one-third of an inning, and two outs counts as two-thirds of an inning. Sometimes, the statistic is written 34.1, 72.2, or 91.0, for example, to represent 34 and 1/3 innings, 72 and 2/3 innings, and 91 innings exactly, respectively.

All-Time MLB leaders in Innings Pitched

• 1. Cy Young | 7354.20

• 2. Pud Galvin | 6003.30

• 3. Walter Johnson | 5914.20

• 4. Phil Niekro | 5404.30

• 5. Nolan Ryan | 5386.00

• 6. Gaylord Perry | 5350.30

• 7. Don Sutton | 5282.30

• 8. Warren Spahn | 5243.20

• 9. Steve Carlton | 5217.30

• 10. Pete Alexander | 5190.00

• 11. Kid Nichols | 5056.30

• 12. Tim Keefe | 5047.20

• 13. Bert Blyleven | 4970.00

• 14. Bobby Mathews | 4956.30

• 15. Mickey Welch | 4802.00

• 16. Tom Seaver | 4782.20

• 17. Christy Mathewson | 4780.20

• 18. Tommy John | 4710.30

• 19. Robin Roberts | 4688.20

• 20. Early Wynn | 4564.00

All pitchers are right handed except Spahn, Carlton, and John.