Pitching for the Twins in 1967, Boswell racked up 204 strikeouts as he, Jim Kaat
and Dean Chance
became the first three pitchers on the same team to strike out 200
each in one season. In 1969 he went 20-12 and was involved in an off-the-field scuffle
with teammate Bob Allison
which resulted in Boswell getting punched by manager Billy
Martin. In the 1969 LCS, he lost to the Orioles 1-0 in ten innings.