From Colorado A&M, Jack Christiansen was chosen in the sixth round of the 1951 NFL Draft, and he came in as a track-star athlete with game-breaking speed. Operating as the catalyst for Detroit’s secondary—famously nicknamed "Chris's Crew"—Christiansen revolutionized the safety position. His closing speed and instincts forced opposing offenses into a strict game plan: don't throw into his zone, and whatever you do, don't punt the ball anywhere near him.

Christiansen made his debut with an outstanding rookie season in 1951, establishing an NFL record by scoring four touchdowns on punt returns. This included a notable single-game achievement against Los Angeles, where he returned two punts for touchdowns—a feat he impressively replicated six weeks later against Green Bay on Thanksgiving. He maintained this momentum throughout 1952, achieving an NFL-record average of 21.5 yards per punt return along with two additional touchdowns. During this period, he also contributed significantly to the secondary, helping Detroit secure its first world championship in 17 years.

In 1953, Christiansen reached his peak performance, transitioning fully to strong safety and delivering one of the most impressive defensive seasons ever. He topped the league with 12 interceptions, including a 92-yard return for a touchdown, helping the Lions secure consecutive NFL Championships against Cleveland. This outstanding year sparked a six-year run of First-Team All-Pro selections (1952–1957), during which he recorded 8 interceptions in 1954 and again in 1956.

The crown jewel of his career came in 1957. Christiansen once again led the NFL in interceptions with 10 takeaways, serving as the defensive general for a squad that dismantled Cleveland 59–14 in the championship game, securing his third world title ring. By the time injuries prompted his retirement after the 1958 season, his eight career punt return touchdowns remained an NFL gold standard for more than three decades.

Statistically, Christiansen played in 89 regular-season games and amassed 46 interceptions for 717 return yards, three pick-sixes, and 85 punt returns for 1,084 yards (a 12.8 career average) with eight touchdowns, alongside three NFL Championship rings. A six-time First-Team All-Pro, five-time Pro Bowler, two-time NFL interception leader, and member of the NFL’s 1950s All-Decade Team, Christiansen was enshrined in the Pro Football Hall of Fame in 1970 and named a charter member of the Pride of the Lions in 2009.