Willett was among the most powerful men on the mound, but was careless about keeping
in shape. After two inauspicious trials, Willett was having his first good season
in 1908 when he suffered an ankle injury; he finished 15-8, 2.28 nonetheless, helping
the Tigers to their second of three straight AL flags. The following season (1909)
was his best, as he went 21-10 with a 2.34 ERA and finished third in the league in
wins and fifth in winning percentage (.677). He was effective in limited bullpen
use in Detroit's losing WS effort.
Willett won 59 games over the next four seasons
for the Tigers, then jumped to the Federal League in 1914 and was one of the few
players to see his effectiveness diminish in the new league. He was 4-16 for the
last-place St. Louis Terriers and didn't finish the 1915 season, his last. He was
the second AL pitcher to hit two HR in a game (6/30/12).