William Frederick Dahlen (January 5, 1870 – December 5, 1950), nicknamed "Bad Bill" for his ferocious temperament, was an American shortstop and manager in Major League Baseball who played for four National League teams from 1891 to 1911. After twice batting over .350 for the Chicago Colts, he starred on championship teams with the Brooklyn Superbas and the New York Giants. At the end of his career he held the major league record for career games played (2,443); he ranked second in walks (1,064, behind Billy Hamilton's 1,187) and fifth in at bats (9,033), and was among the top ten in runs batted in (1,234), doubles (414) and extra base hits (661). He was also among the NL's top seven players in hits (2,461; some sources list totals up to 2,471), runs (1,589), triples (163) and total bases (3,447). After leading the league in assists four times and double plays three times, he set major league records for career games (2,132), putouts (4,850), assists (7,500), total chances (13,325) and double plays (881) as a shortstop; he still holds the record for total chances, and is second in putouts and fourth in assists. His 42-game hitting streak in 1894 was a record until 1897, and remains the fourth longest in history and the longest by a right-handed NL hitter.