mo is probably just a fluke and is only good in the postseason like decude says
Rank Player (yrs, age) Earned Run Average Throws 1. Ed Walsh+ (14) 1.816 R 2. Addie Joss+ (9) 1.887 R 3. Jim Devlin (5) 1.896 R 4. Jack Pfiester (8) 2.024 L 5. Smoky Joe Wood (14) 2.033 R 6. Mordecai Brown+ (14) 2.057 R 7. Monte Ward+ (17) 2.099 R 8. Christy Mathewson+ (17) 2.133 R Al Spalding+ (8) 2.133 R 10. Tommy Bond (10) 2.138 R 11. Rube Waddell+ (13) 2.161 L 12. Walter Johnson+ (21) 2.167 R 13. Mariano Rivera (19, 43) 2.209 R 14. Jake Weimer (7) 2.231 L 15. Orval Overall (7) 2.233 R 16. Will White (10) 2.276 R 17. Babe Ruth+ (22) 2.277 L