After the season, Hart was left to be the starter. For the 1967 season, he started all 14 contests, going 6-7-1 while throwing for 3,008 yards with 19 touchdowns and 30 interceptions on a 48.4 completion percentage. Both his yards and interceptions would prove to be career highs. The following year, he and the team improved slightly, with him going 8-3-1 in the 12 games he started (with Johnson starting two games), throwing for 2,059 yards with 15 touchdowns to 18 interceptions on a 44.3 completion percentage. Hart split time with Johnson for the 1969 season, playing in nine games while starting five (with Johnson starting the other nine), and he went 2-3 with 1,086 yards for six touchdowns and 12 interceptions on a 49.7 completion percentage, although the team won just four games for the first time since 1962.