| Year | Team | RS | Lead | % of lead | RA | Lead | % of lead | Pyth. | ||
| 1998 | Yankees | 965 | 1 | 965 | 100.00 | 656 | 1 | 656 | 100.00 | 0.68 |
| 1997 | Marlins | 740 | 7 | 923 | 80.17 | 669 | 4 | 581 | 115.15 | 0.55 |
| 1996 | Yankees | 871 | 9 | 993 | 87.71 | 787 | 2 | 769 | 102.34 | 0.55 |
| 1995 | Braves | 645 | 8 | 785 | 82.17 | 540 | 1 | 540 | 100.00 | 0.59 |
| 1993 | Toronto | 847 | 2 | 899 | 94.22 | 742 | 5 | 664 | 111.75 | 0.57 |
| 1992 | Toronto | 780 | 2 | 791 | 98.61 | 682 | 8 | 604 | 112.91 | 0.57 |
| 1991 | Twins | 776 | 4 | 829 | 93.61 | 652 | 3 | 622 | 104.82 | 0.59 |
| 1990 | Reds | 693 | 5 | 775 | 89.42 | 597 | 1 | 597 | 100.00 | 0.57 |
| Decade Averages | 789.625 | 4.75 | 870 | 90.74 | 665.625 | 3.125 | 629.125 | 105.87 | 0.58 | |
| 1989 | A's | 712 | 4 | 774 | 91.99 | 596 | 1 | 596 | 100.00 | 0.59 |
| 1988 | Dodgers | 628 | 6 | 703 | 89.33 | 544 | 2 | 532 | 102.26 | 0.57 |
| 1987 | Twins | 786 | 8 | 896 | 87.72 | 806 | 9 | 655 | 123.05 | 0.49 |
| 1986 | Mets | 783 | 1 | 783 | 100.00 | 578 | 2 | 569 | 101.58 | 0.65 |
| 1985 | Royals | 687 | 13 | 839 | 81.88 | 639 | 2 | 588 | 108.67 | 0.54 |
| 1984 | Detriot | 829 | 1 | 829 | 100.00 | 643 | 1 | 643 | 100.00 | 0.62 |
| 1983 | O's | 799 | 2 | 800 | 99.88 | 652 | 3 | 609 | 107.06 | 0.60 |
| 1982 | Cards | 685 | 5 | 739 | 92.69 | 609 | 1 | 609 | 100.00 | 0.56 |
| 1981 | Dodgers | 450 | 4 | 491 | 91.65 | 356 | 2 | 331 | 107.55 | 0.62 |
| 1980 | Philly | 728 | 2 | 738 | 98.64 | 639 | 5 | 589 | 108.49 | 0.56 |
| Decade Averages | 708.7 | 4.6 | 759.2 | 93.38 | 606.2 | 2.8 | 572.1 | 105.87 | 0.58 | |
| 1979 | Pirates | 775 | 1 | 775 | 100.00 | 643 | 3 | 581 | 110.67 | 0.59 |
| 1978 | Yankees | 735 | 4 | 804 | 91.42 | 582 | 1 | 582 | 100.00 | 0.61 |
| 1977 | Yankees | 831 | 4 | 867 | 95.85 | 651 | 1 | 651 | 100.00 | 0.62 |
| 1976 | Reds | 857 | 1 | 857 | 100.00 | 633 | 5 | 538 | 117.66 | 0.65 |
| 1975 | Reds | 840 | 1 | 840 | 100.00 | 586 | 3 | 534 | 109.74 | 0.67 |
| 1974 | A's | 689 | 3 | 696 | 98.99 | 551 | 1 | 551 | 100.00 | 0.61 |
| 1973 | A's | 758 | 1 | 758 | 100.00 | 615 | 3 | 561 | 109.63 | 0.60 |
| 1972 | A's | 604 | 2 | 640 | 94.38 | 457 | 2 | 430 | 106.28 | 0.64 |
| 1971 | Pirates | 788 | 1 | 788 | 100.00 | 599 | 5 | 550 | 108.91 | 0.63 |
| 1970 | Baltimore | 792 | 1 | 792 | 100.00 | 574 | 1 | 574 | 100.00 | 0.66 |
| Decade Averages | 766.9 | 1.9 | 781.7 | 98.06 | 589.1 | 2.5 | 555.2 | 106.29 | 0.63 | |
| 1969 | Mets | 632 | 9 | 798 | 79.20 | 541 | 2 | 540 | 100.19 | 0.58 |
| 1968 | Detroit | 671 | 1 | 671 | 100.00 | 492 | 1 | 492 | 100.00 | 0.65 |
| 1967 | St. Louis | 695 | 2 | 702 | 99.00 | 557 | 2 | 551 | 101.09 | 0.61 |
| 1966 | Baltimore | 755 | 1 | 755 | 100.00 | 601 | 4 | 517 | 116.25 | 0.61 |
| 1965 | Dodgers | 608 | 8 | 825 | 73.70 | 521 | 1 | 521 | 100.00 | 0.58 |
| 1964 | St. Louis | 715 | 2 | 803 | 89.04 | 652 | 7 | 566 | 115.19 | 0.55 |
| 1963 | Dodgers | 640 | 6 | 747 | 85.68 | 550 | 1 | 550 | 100.00 | 0.58 |
| 1962 | Yankees | 817 | 1 | 817 | 100.00 | 680 | 2 | 658 | 103.34 | 0.59 |
| 1961 | Yankees | 827 | 2 | 841 | 98.34 | 612 | 2 | 588 | 104.08 | 0.65 |
| 1960 | Pirates | 734 | 1 | 734 | 100.00 | 593 | 1 | 593 | 100.00 | 0.61 |
| Decade Averages | 709.4 | 3.3 | 769.3 | 92.50 | 579.9 | 2.3 | 557.6 | 104.01 | 0.60 | |
| 1959 | Dodgers | 705 | 3 | 764 | 92.28 | 670 | 3 | 613 | 109.30 | 0.53 |
| 1958 | Yankees | 759 | 1 | 759 | 100.00 | 577 | 2 | 575 | 100.35 | 0.63 |
| 1957 | Braves | 772 | 1 | 772 | 100.00 | 613 | 2 | 591 | 103.72 | 0.61 |
| 1956 | Yankees | 857 | 1 | 857 | 100.00 | 631 | 2 | 598 | 105.52 | 0.65 |
| 1955 | Dodgers | 857 | 1 | 857 | 100.00 | 650 | 1 | 650 | 100.00 | 0.63 |
| 1954 | Yankees | 805 | 1 | 805 | 100.00 | 563 | 3 | 504 | 111.71 | 0.67 |
| 1953 | Yankees | 801 | 1 | 801 | 100.00 | 547 | 1 | 547 | 100.00 | 0.68 |
| 1952 | Yankees | 727 | 2 | 763 | 95.28 | 557 | 1 | 557 | 100.00 | 0.63 |
| 1951 | Yankees | 798 | 2 | 804 | 99.25 | 621 | 2 | 594 | 104.55 | 0.62 |
| 1950 | Yankees | 914 | 2 | 1027 | 89.00 | 691 | 2 | 654 | 105.66 | 0.64 |
| Decade Averages | 799.5 | 1.5 | 820.9 | 97.58 | 612 | 1.9 | 588.3 | 104.08 | 0.63 | |
| 1949 | Yankees | 829 | 2 | 896 | 92.52 | 637 | 2 | 574 | 110.98 | 0.63 |
| 1948 | Cleveland | 840 | 3 | 907 | 92.61 | 568 | 1 | 568 | 100.00 | 0.69 |
| 1947 | Yankees | 794 | 1 | 794 | 100.00 | 568 | 1 | 568 | 100.00 | 0.66 |
| 1946 | St. Louis | 712 | 1 | 712 | 100.00 | 545 | 1 | 545 | 100.00 | 0.63 |
| 1945 | Detroit | 633 | 2 | 676 | 93.64 | 565 | 4 | 548 | 103.10 | 0.56 |
| 1944 | St. Louis | 772 | 1 | 772 | 100.00 | 490 | 1 | 490 | 100.00 | 0.71 |
| 1943 | Yankees | 669 | 1 | 669 | 100.00 | 542 | 1 | 542 | 100.00 | 0.60 |
| 1942 | St. Louis | 755 | 1 | 755 | 100.00 | 482 | 1 | 482 | 100.00 | 0.71 |
| 1941 | Yankees | 830 | 2 | 865 | 95.95 | 631 | 1 | 631 | 100.00 | 0.63 |
| 1940 | Reds | 707 | 3 | 809 | 87.39 | 528 | 1 | 528 | 100.00 | 0.64 |
| Decade Averages | 754.1 | 1.7 | 785.5 | 96.21 | 555.6 | 1.4 | 547.6 | 101.41 | 0.65 | |
| 1939 | Yankees | 967 | 1 | 967 | 100.00 | 556 | 1 | 556 | 100.00 | 0.75 |
| 1938 | Yankees | 966 | 1 | 966 | 100.00 | 710 | 1 | 710 | 100.00 | 0.65 |
| 1937 | Yankees | 979 | 1 | 979 | 100.00 | 671 | 1 | 671 | 100.00 | 0.68 |
| 1936 | Yankees | 1065 | 1 | 1065 | 100.00 | 731 | 1 | 731 | 100.00 | 0.68 |
| 1935 | Detroit | 919 | 1 | 919 | 100.00 | 665 | 2 | 632 | 105.22 | 0.66 |
| 1934 | St. Louis | 799 | 1 | 799 | 100.00 | 656 | 3 | 583 | 112.52 | 0.60 |
| 1933 | Giants | 636 | 4 | 687 | 92.58 | 515 | 1 | 515 | 100.00 | 0.60 |
| 1932 | Yankees | 1002 | 1 | 1002 | 100.00 | 724 | 2 | 716 | 101.12 | 0.66 |
| 1931 | Cardinals | 815 | 2 | 828 | 98.43 | 614 | 2 | 599 | 102.50 | 0.64 |
| 1930 | A's | 951 | 2 | 1062 | 89.55 | 751 | 2 | 689 | 109.00 | 0.62 |
| Decade Averages | 909.9 | 1.5 | 927.4 | 98.06 | 659.3 | 1.6 | 640.2 | 103.04 | 0.65 | |
| 1929 | A's | 901 | 2 | 926 | 97.30 | 615 | 1 | 615 | 100.00 | 0.68 |
| 1928 | Yankees | 894 | 1 | 894 | 100.00 | 685 | 2 | 615 | 111.38 | 0.63 |
| 1927 | Yankees | 975 | 1 | 975 | 100.00 | 599 | 1 | 599 | 100.00 | 0.73 |
| 1926 | Cardinals | 817 | 1 | 817 | 100.00 | 678 | 3 | 602 | 112.62 | 0.59 |
| 1925 | Pirates | 912 | 1 | 912 | 100.00 | 715 | 3 | 643 | 111.20 | 0.62 |
| 1924 | Washington | 755 | 5 | 849 | 88.93 | 613 | 1 | 613 | 100.00 | 0.60 |
| 1923 | Yankees | 823 | 3 | 888 | 92.68 | 622 | 1 | 622 | 100.00 | 0.64 |
| 1922 | Giants | 852 | 3 | 865 | 98.50 | 658 | 1 | 658 | 100.00 | 0.63 |
| 1921 | Giants | 840 | 1 | 840 | 100.00 | 637 | 2 | 595 | 107.06 | 0.63 |
| 1920 | Cleveland | 857 | 1 | 857 | 100.00 | 642 | 2 | 629 | 102.07 | 0.64 |
| Decade Averages | 862.6 | 1.9 | 882.3 | 97.74 | 646.4 | 1.7 | 619.1 | 104.43 | 0.64 | |
| 1919 | Reds | 577 | 2 | 605 | 95.37 | 401 | 1 | 401 | 100.00 | 0.67 |
| 1918 | Red Sox | 474 | 4 | 504 | 94.05 | 380 | 1 | 380 | 100.00 | 0.61 |
| 1917 | White Sox | 656 | 1 | 656 | 100.00 | 464 | 2 | 454 | 102.20 | 0.67 |
| 1916 | Red Sox | 550 | 6 | 670 | 82.09 | 480 | 1 | 480 | 100.00 | 0.57 |
| 1915 | Red Sox | 669 | 3 | 778 | 85.99 | 499 | 2 | 491 | 101.63 | 0.64 |
| 1914 | Braves | 657 | 2 | 672 | 97.77 | 548 | 3 | 540 | 101.48 | 0.59 |
| 1913 | A's | 794 | 1 | 794 | 100.00 | 592 | 4 | 498 | 118.88 | 0.64 |
| 1912 | Red Sox | 799 | 1 | 799 | 100.00 | 544 | 1 | 544 | 100.00 | 0.68 |
| 1911 | A's | 861 | 1 | 861 | 100.00 | 601 | 1 | 601 | 100.00 | 0.67 |
| 1910 | A's | 673 | 2 | 679 | 99.12 | 441 | 1 | 441 | 100.00 | 0.70 |
| Decade Averages | 671 | 2.3 | 701.8 | 95.44 | 495 | 1.7 | 483 | 102.42 | 0.64 | |
| 1909 | Pittsburgh | 699 | 1 | 699 | 100.00 | 447 | 2 | 390 | 114.62 | 0.71 |
| 1908 | Cubs | 624 | 2 | 652 | 95.71 | 461 | 3 | 445 | 103.60 | 0.65 |
| 1907 | Cubs | 574 | 2 | 634 | 90.54 | 390 | 1 | 390 | 100.00 | 0.68 |
| 1906 | White Sox | 570 | 3 | 663 | 85.97 | 460 | 1 | 460 | 100.00 | 0.61 |
| 1905 | Giants | 780 | 1 | 780 | 100.00 | 505 | 2 | 442 | 114.25 | 0.70 |
| 1903 | Pilgrims | 708 | 1 | 708 | 100.00 | 504 | 1 | 504 | 100.00 | 0.66 |
| Decade Averages | 659.17 | 1.67 | 689.33 | 95.37 | 461.17 | 1.67 | 438.50 | 105.41 | 0.67 | |
| 1892 | Beaneaters | 862 | 2 | 935 | 92.19 | 649 | 2 | 613 | 105.87 | 0.64 |
| 1890 | Brooklyn | 884 | 1 | 884 | 100.00 | 620 | 1 | 620 | 100.00 | 0.67 |
| 1889 | Giants | 935 | 1 | 835 | 111.98 | 708 | 2 | 626 | 113.10 | 0.64 |
| 1888 | Giants | 659 | 4 | 734 | 89.78 | 479 | 1 | 479 | 100.00 | 0.65 |
| 1887 | Detroit | 969 | 1 | 969 | 100.00 | 714 | 2 | 702 | 101.71 | 0.65 |
| 1886 | Browns | 944 | 1 | 944 | 100.00 | 592 | 1 | 592 | 100.00 | 0.72 |
| 1885 | White Stockings | 834 | 1 | 834 | 100.00 | 470 | 2 | 370 | 127.03 | 0.76 |
| 1884 | Providence | 665 | 5 | 834 | 79.74 | 388 | 1 | 388 | 100.00 | 0.75 |
| Decade Averages | 844.00 | 2.00 | 871.13 | 96.71 | 577.50 | 1.50 | 548.75 | 105.96 | 0.68 | |
| TOTAL AVERAGES | 772.99 | 2.46 | 807.31 | 95.70 | 589.68 | 2.02 | 565.54 | 104.34 | 0.63 | |
| Champions leading in RS: | 49 | |||||||||
| Champions leading in RA: | 48 | |||||||||
| Champions leading both: | 20 | |||||||||