Boston again won the NL in 1898 while Tenney hit .328 with 62 RBIs. In 1899 he collected 209 hits, fifth most in MLB, and recorded 17 triples, good for fourth best in MLB. In 1900 Tenney, at age 28, batted .279 over 112 games played. He began a streak of seven consecutive seasons where he led the NL in assists in 1901; he holds the record for most seasons leading a league in assists, with eight, including one in 1899. He was suspended for ten games for fighting Pittsburgh Pirates manager Fred Clarke in May 1902, and finished the 1902 season with the second most sacrifice hits (29) in the majors, to go along with a .315 average. Throughout the 1901–1902 seasons, Tenney received contract offers worth up to $7,000 ($206,248 in 2017) from St. Louis, Cleveland, and Detroit; Tenney, however, decided to remain in Boston, and was named captain of the club in 1903. For the season, he hit .313, with 41 RBIs and three home runs, as he led his team in walks (70) and had the best on-base percentage mark (.415) on the squad. In 1904, Tenney again led his team in walks and on-base percentage, as he tied for the team lead in runs with Ed Abbaticchio.