Three infielders performed unassisted triple plays (UTPs) with the Cleveland Naps/Indians, while two did the same while playing for the Boston Red Sox and Philadelphia Phillies.

Under MLB rules, when a ball is put into play, if the bases are loaded, each player on base must run to the next base. When a fielder catches the ball on the fly, the batter is out and all runners must return to his original base. Stepping on the nearest base puts out the runner running to that base. Tagging the runner returning to that same base completes the UTP.

Naps Shortstop Neal Ball made the play in the second inning of the July 19, 1909 game against the Boston Red Sox. Indians Second-baseman performed the UTP 20 years later, in the fifth inning of the fifth game of the 1920 World Series against the Boston Braves. It was 88 years later that Indians Second-baseman Asdrúbal Cabrera repeated the feat, in fifth inning of the May 12, 2008 game against the Toronto Blue Jays.

Red Sox UTP achievers were First-baseman George Burns, in the second inning of the September 14, 1923 game against the Indians and Shortstop John Valentin, in the sixth inning of the July 8, 1994 game against the Seattle Mariners.

For the Phillies, Second-baseman Mickey Morandini pulled off a UTP against Philadelphia’s cross-state rivals, the Pittsburgh Pirates, in the sixth inning on September 20, 1992; and Second-baseman Eric Bruntlett ended the August 23, 2009 game against the New York Mets with a UTP.

More Info: en.wikipedia.org