A flashy fielder with cat-like agility, Cassidy was one of the first to play in the majors with no minor league experience. His 19 triples for the 1904 Senators tied him for the league lead and set a still-standing rookie record. He led AL shortstops with 520 assists and 66 errors in 1905, and was considered a top young shortstop when he died of malaria in the spring of 1906.
