Alley was a modest hitter but an exceptionally steady shortstop with good range and an accurate throwing arm. He won two Gold Glove Awards at shortstop (1966–67) and garnered two All-Star appearances primarily on the strength of his glove. He spent most of his career turning double plays with Baseball Hall of Famesecond basemanBill Mazeroski, and the duo set an MLB record of 161 double plays in a season in 1966 that still stands (when the Pirates set a National League record with 215 total double plays). They also joined a select list of eight shortstop-second baseman duos to each win a Gold Glove the same season while playing together twice (1967–68). Shoulder and knee problems ultimately ended his career and prevented him from realizing his full potential.