15. New York Yankees, 1956-61
This was a transitional portion of the Yankee dynasty. Whitey Ford and Mickey Mantle were still great, but Phil Rizzuto retired in 1956 and Yogi Berra and Hank Bauer gradually ceded playing time to Elston Howard and Roger Maris. The Yanks missed only an occasional beat, winning pennants annually save for 1959. Their World Series titles came in 1956, 1958 and 1961, and their 1957 and 1960 losses both occurred in the seventh game. The six-season record of 572-364 works out to a .611 percentage.
14. Cincinnati Reds, 1972-77
The Big Red Machine rolled up NL West titles in 1972, 1973, 1975 and 1976, beating Boston for the 1975 World Series and sweeping the Yankees in 1976. The cast barely changed; Johnny Bench at catcher, Joe Morgan at second, Tony Perez at first, George Foster in left, and Pete Rose flitting about as needed. The Reds were a combined 590-375 for the period, a .611 percentage.
13. New York Yankees, 1998-2003
The last great Yankee dynasty was led by Derek Jeter and Mariano Rivera, both now Hall of Famers. The Yanks won a franchise record 114 games in 1998, defeating San Diego for the first of three straight World Series wins. The Braves would fall in 1999, the Mets in 2000. Their Game 7 walkoff defeat by Arizona in 2001 is the stuff of legend. For the six-season window, the Yankees stood 598-371, a .617 winning percentage.
12. Houston Astros, 2017-22
Now we arrive at the Astros, whose ongoing stretch works out superior to all of the best dynasties of the past half century. In fact, the most powerful dynasty we will see among the 11 teams ahead of the Astros played its last game nearly two-thirds of a century ago. Since 2017, the Astros have won 541 games against just 329 defeats, a .622 winning percentage.
11. Philadelphia Athletics, 1909-1914
Connie Mack’s first dynasty — his second is yet to come on this list — dominated the first two decades of the American League. Between 1910 and 1914, Mack won all but one pennant, defeating the National League champion Cubs in 1910 and the Giants in both 1911 and 1913. Heavily favored in 1914, they lost in four games to the lightly regarded Boston Braves in probably the greatest upset of Series history. For the six-season window, the A’s of Eddie Collins, Chief Bender, Eddie Plank and Home Run Baker ran up a 583-341 record, a .631 percentage.