Dahlen was born in Nelliston, New York at the corner of Berthoud and Dahlen and East Main. He was a very good hitter and had a good amount of power for the dead-ball era. He began his career with the Colts in 1891, and during his eight years with the team finished among the NL's top ten players in home runs four times and in slugging average three times. He also scored over 100 runs with 10 or more triples in each of his first six seasons; in 1894 he posted the highest batting average to that time by a major league shortstop (various sources state .357 or .362), and he followed with a .352 average in 1896. His 1894 season included a record 42-game hitting streak from June 20 to August 6, surpassing the 33-game streak by George Davis one year earlier. Amazingly, after going 0-for-6 in the next game, a 10-inning contest on August 7, Dahlen pulled off another 28-game streak, ending up having hit in 70 of 71 games. His mark was broken three years later by Willie Keeler, who hit in 44 straight; that NL record was eventually tied by Pete Rose. Only Joe DiMaggio, with his 56-game streak in 1941, has bettered Dahlen's mark among right-handed batters. Dahlen also twice hit three triples in a game, and once he tripled twice in one inning (August 30, 1900).
Prior to the 1899 season, Dahlen was traded by Chicago, and ended up in Brooklyn after another deal. His new team won the NL title in each of his first two seasons, and although his batting average had dropped from that of earlier years, he compensated by continuing to accumulate numerous walks and stolen bases and by playing outstanding defense. In 1902, he finished fourth in the NL with 74 RBI. In 1903 he set an NL record for fielding percentage with a .948 average, breaking George Wright's 1878 mark of .947; Tommy Corcoran broke his record in 1905 with a .952 average.
Bill Dahlen, circa 1908
After the 1903 season, Dahlen was traded to the Giants, the team he'd always strived to play for, in exchange for pitcherJack Cronin and Charlie Babb. While Cronin and Babb contributed only three bad years to Brooklyn, Dahlen posted great numbers with the Giants, leading the league with 80 RBI in his first year, 1904. In 1905 he was again among the RBI leaders, despite hitting only .242, as the Giants won their first World Series title. Although he was hitless in the five-game Series, he contributed with flawless defense and by drawing three walks and stealing three bases. He was often considered one of the quietest players in the game, keeping to himself most of the time. After the 1907 season, he was traded to the Boston Doves, for whom he played his last two full seasons. In 1909 he broke Jake Beckley's record of 2386 career games; his record was broken in turn by Honus Wagner in 1914. He was named Brooklyn's manager for the 1910 season, but never finished above 6th place in four seasons. His last playing appearances were three games as a pinch-hitter in 1910, and one game at shortstop in 1911.
In a 21-season career, Dahlen batted .272; his 84 home runs were then among the fifteen highest totals in history, and ranked behind only Herman Long (91) among shortstops. His 289 stolen bases after the statistic was redefined in 1898 were then among the ten highest totals, as were his 547 total steals since they were first recorded in 1887. His records for games and putouts at shortstop were broken by Rabbit Maranville, and his mark for assists was surpassed by Luis Aparicio, with his NL record standing until Ozzie Smith broke it in 1993; his record for double plays was broken by Roger Peckinpaugh. Dahlen's 14,566 total chances at all positions have been surpassed by only Maranville (16,091) and Wagner (15,536). In four years as a manager, all for Brooklyn, he posted a 251-355 record for a .414 winning percentage; he earned his nickname with a ferocious arguing style which drew 65 ejections as a manager, still among the top ten in history.
Dahlen was featured in David Pietrusza's 1995 television documentary "Local Heroes" in the segment "Knocking on Cooperstown's Door."
Dahlen was included on the Veterans Committee ballot for 2013 induction to the Hall of Fame. The results were announced on December 3, 2012. Dahlen received 10 out of 16 votes, falling 2 votes short of election, the highest total of any person on the ballot who was not elected and will have to wait until the end of 2015 for election.