Willis won 24 games for Boston as a rookie in 1898 and became the anchor of the club’s pitching staff for eight years. On August 7, 1899, he won a 7-1 no-hitter against Washington. With a splendid curveball, the durable Willis hurled more than 300 innings eight times; in 1902, he threw a league-high 410 innings and set a modern NL record with 45 complete games. He completed 388 of his 471 career starts.
In 1903, both the American and National Leagues laid claim to Willis’s contract, but his services were finally retained by NL Boston. He lost a league-high 25 games in 1904, and in 1905 he set a modern ML record with 29 losses for the first team in history to have four 20-game losers. He regained his winning ways with Pittsburgh, with four consecutive 20-win seasons and a combined 89-46 record with strong clubs from 1906 through 1909. He threw 50 career shutouts, but was on the losing end of 37 others.