While having only a .254 career batting average, he was considered a good clutch hitter (Carl Yastrzemski wrote in his autobiography "Baseball, The Wall, and Me" "That man was one of the coolest clutch hitters I had seen"). However, his greatest strength was his defensive ability. Adair set then-major league records for single-season fielding percentage (.994) and fewest errors (5) in 1964, and followed that up by leading the league in fielding percentage again in 1965. He also set a record for consecutive errorless games by a second baseman (89), and consecutive chances handled without an error (458) from July 22, 1964 through May 6, 1965. In addition, he was considered a "gamer" who would often play when injured.