After 2003's failed attempt to focus on the passing game, the 2004 team returned to the typical Steelers formula, a run-heavy offense (61/39 run-pass ratio) and a strong defense. The team's dominant running game, featuring Jerome Bettis and Duce Staley (acquired prior to the season in free agency), was bolstered by an efficient and often explosive passing attack led by Roethlisberger and receivers Burress, Ward, and Antwaan Randle El. The defense, one of the league's best, was anchored by Pro Bowl linebackers James Farrior and Joey Porter and Pro Bowl safety Troy Polamalu. Only three previous teams (The '84 49ers, the '85 Bears, & the '98 Vikings) had a 15-win season, with the Steelers being the first AFC team to accomplish this feat. As a result of this dominant season, the Steelers received home field advantage throughout the AFC playoffs.