 When Arnold Johnson (a friend of Topping and Yankees general manager George Weiss) became the owner of the Kansas City Athletics in 1955, his new team made many transactions with the Yankees. From 1956 to 1960, the Athletics traded many young players to the Yankees for cash and aging veterans. The trades strengthened the Yankees'roster, but brought criticism from rival clubs. Before their 1960 season, the Yankees made one such trade with the Athletics in which they acquired outfielder Roger Maris. In his first Yankees season, Maris led the league in slugging percentage, RBIs, and extra base hits, finished second with 39 home runs, and won the AL MVP Award. The 1960 Yankees won the AL pennant for the 10th time in 12 years under Stengel, and outscored the Pirates 55 – 27 in the seven World Series games. However, the team lost four of them, falling short of a Series championship after Bill Mazeroski hit a walk-off home run in the final game, ending a contest that Appel called "one of the most memorable in baseball history." The season turned out to be Stengel's last as Yankees manager; he indicated that his age played a role in the team's decision, saying, "I'll never make the mistake of being seventy again."
