Arriving in Denver as the 20th overall pick in the 1989 NFL Draft, the imposing safety out of Arkansas immediately redefined physical play in the Broncos' secondary. Standing 6-foot-3 and weighing 218 pounds, Steve Atwater brought a linebacker's size and a sprinter's range to the free safety position, earning runner-up honors for NFL Defensive Rookie of the Year while helping propel Denver to an appearance in Super Bowl XXIV.

Nicknamed "The Smiling Assassin" for his cheerful personality off the field and fierce tackling on it, Atwater quickly became one of the league's most formidable enforcers. From 1990 to 1996, he enjoyed a period of dominance, earning seven straight Pro Bowl selections. During his prime, he received First-Team All-Pro honors in 1991 and 1992, and a Second-Team award in 1996. He was a consistent leader in tackles and expertly shut down deep passing routes.

His 1991 First-Team All-Pro season saw him achieve a career-high 150 tackles and five interceptions, showcasing his rare ability to play as an extra linebacker in the box against the run without compromising pass coverage. In 1992, he earned his second First-Team honors with 121 tackles and two interceptions, cementing his status as the AFC's top all-around safety. During this period, he made his most famous play—a legendary, bone-jarring collision on Monday Night Football in 1990 that stopped 260-pound Chiefs fullback Christian Okoye in his tracks.

Atwater's elite instincts and physical presence were the heartbeat of the defense as Denver evolved into a championship powerhouse late in the decade. He logged 126 tackles in 1995 and another 117 in 1996, consistently setting a ruthless physical tone for the entire unit. Opposing receivers routinely dropped passes over the middle in anticipation of Atwater's arrival, allowing Denver's defensive coordinators to run aggressive, opportunistic schemes up front.

As his tenure with the Denver Broncos and the Miami Dolphins reached its zenith, Atwater served as a pivotal figure in the defensive backfield for the Broncos' consecutive championship-winning teams. His most notable postseason performance occurred in Super Bowl XXXII against Green Bay, where he delivered an outstanding display with six tackles, a sack, a forced fumble, and a decisive pass breakup in the late stages of the game, which involved a mid-air collision knocking out three players, thereby securing Denver's inaugural Lombardi Trophy. He subsequently earned a second championship ring in Super Bowl XXXIII before concluding his professional career with a single season with the New York Jets in 1999.

Over his career, Atwater appeared in 155 regular-season games, compiling 24 interceptions, 1,074 tackles, and 5.0 sacks, while earning a spot on the NFL 1990s All-Decade Team. The Broncos inducted him into the Ring of Fame in 2007, culminating in his enshrinement into the Pro Football Hall of Fame in 2020.