On Friday night, Barry Sanders was among 12 former running backs who were named to the NFL's 100th Anniversary Team. Two days later, Sanders watched as Bills running back Frank Gore passed him on the NFL's career rushing list. 

During Sunday's game against the Broncos, Gore, a 15-year NFL veteran, surpassed Sanders' career total of 15,269 career rushing yards. He finished with 65 yards on 15 carries in Buffalo's 20-3 win. Hall of Fame running backs Walter Payton (16,726 yards) and Emmitt Smith (18,355 yards) are the only running backs ahead of Gore on the all-time list. 

How did Gore get to this point, and how does it continue to churn out yards at the age of 36? While much of Gore's success should be attributed to his work ethic, drive, and dedication to his craft, Gore has also taken advantage of some fortunate circumstances that helped get him to this point. 

Before turning pro, Gore was a member of one of the most talented teams in college football history, the early 2000s Miami Hurricanes. Those Hurricane teams were especially deep at the running back position, a group that included future NFL Pro Bowlers Clinton Portis, Willis McGahee, and Gore. The group also included Payton's son, Jarrett, who started ahead of Gore in 2003 after Portis and McGahee turned pro. 

Gore, who won a national championship as a freshman before tearing his ACL the following spring, didn't start for Miami until 2004. That season he rushed for 945 yards and eight touchdowns while averaging 4.8 yards per carry. He finished his college career with just 348 carries, a considerably light workload that has likely contributed to his long NFL career. In comparison, Hall of Fame running back Earl Campbell, who was also recently named to the NFL's 100th Anniversary Team, had 765 carries during his time at the University of Texas. While he enjoyed a prolific career, Campbell's body began to wear down just several years into his NFL career, leading to his retirement before his 31st birthday. 

While Gore has been a starting running back since his second NFL season, he has never received a heavy workload in terms of carries. Only once, his second season, has Gore carried the ball over 300 times. During his first 14 seasons, Gore averaged 242 carries per season. By comparison, Jerome Bettis, who is eighth on the all-time rushing list, had five seasons of at least 300 carries during his first eight NFL seasons that included a league-high 375 carries in 1997. Bettis' body began breaking down in 2005, his 13th and final NFL season. Eddie George, the 1995 Heisman Trophy winner who helped power to the Titans to a Super Bowl appearance in 1999, had a whopping 2,733 attempts in eight seasons in Tennessee, receiving at least 300 carries each season that included a league-high 403 attempts in 2000. The heavy workload ultimately took its toll on George, who retired after nine seasons at the age of 31. 

What makes Gore special is his ability to make an impact on a game without needing 30 carries to do so. He has averaged over 4.0 yards per carry for a season on 11 different occasions. He's averaged at least 4.6 yards per carry five times, including a career high 5.4 yards per carry in 2006. In 2012, the year he helped lead the 49ers to the Super Bowl, Gore averaged 4.7 yards per carry while earning his second of three straight Pro Bowl selections. Gore has also been an underrated pass catcher, with 464 career receptions and 18 career touchdown catches. 

Gore, who spent the first decade of his career with the 49ers, also had the luxury of playing behind a talented offensive line in San Francisco that included perennial Pro Bowlers Joe Staley and Mike Iupati. With Staley and Iupati helping lead the way, Gore became the 49ers' all-time leading rusher while helping revive a 49ers franchise that was a completed pass away from winning its sixth Super Bowl title at the end of the 2012 season. 

It should also be noted that Gore is among the NFL's most intelligent backs. He rarely allows himself to accept big hits by opposing defenders, as Gore -- who is also a small target at 5-foot-9 and 212 yards -- routinely runs low while keeping his shoulders square, two traits that running backs are taught at a young age. Some running backs do that better than others with it comes to being effective while also running in a manner that protects them. Very few have done that better than Gore. 

How much longer will Gore continue to play? The answer to that question is anyone's guess. One thing we do know is that Gore's remarkable durability so far will eventually lead to a place for him in the Pro Football Hall of Fame.