In 129 games in his career, O’Brien was successful on 2,110 of his 3,602 tries for a total of 25,094 yards. He totaled 194.5 yds per game through the air. O’Brien passed for 128 touchdowns while tossing 98 interceptions. He lost a combined 2,118 yds while being sacked 353 different times. His touchdown rate when attempting a pass was 3.6% and his interception percentage was 2.7%.
O’Brien completed 0 of his attempted 0 throws in his last season for a completion percentage of 0.0%. His longest completion was for 0 yds and he passed for 0.0 yds per outing. His quarterback rating was 0.0 with a TD percentage of 0.0% and an interception rate of 0.0%. In his final season, O’Brien passed for 0 yds with 0 TDs and 0 interceptions. He was sacked 0 different times for a total of 0 yds lost.