On Wednesday, Oklahoma head coach Bob Stoops announced his retirement after 18 successful seasons in Norman. Stoops led the Sooners to a national title, 18 consecutive bowl berths, and 10 Big 12 titles, along with a number of other impressive accolades.

But with Stoops’ retirement, one interesting statistic now remains in college football, and that is that there are now just four active head coaches left in the sport who have won a national title. Those four include Alabama’s Nick Saban, Clemson’s Dabo Swinney, Florida State’s Jimbo Fisher, and Ohio State’s Urban Meyer.

This number may sound small, which it is, but we saw this same number when former LSU head coach Les Miles was fired in 2016. After this, there were only four remaining in Saban, Fisher, Meyer, and Stoops. This was one of the lowest totals in awhile. According to the USA Today, there was well over that number back in 2006.

To put that microscopic total into perspective, look back a decade ago to the 2006 season, when there were 14 active head coaches with a national championship — a number that included not just Meyer and Stoops, but coaches such as Mack Brown, Pete Carroll, Larry Coker and Jim Tressel, among others.

With Swinney’s most recent national title win over Alabama, the Clemson head coach simply replaced Stoops from that last four-man list from 2016. Depending on if one of those head coaches retires or gets fired in the coming years, there’s a chance we could see that number get even lower, if a new national title head coach doesn’t emerge before then.