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 also garnered two All-Star appearances primarily on the strength of his glove. He spent most of his career turning double plays with second baseman Bill Mazeroski, and the duo set a MLB record of 161 double plays in a season in 1966 that still stands (when the Pirates set a NL 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.