The Broncos are No. 1 in something.

They lead professional football in this achievement: A team’s former starting quarterbacks who are backups today.

The number is 7, and Ol’ No. 7 was responsible for all.

And if, as prophesied by most alleged experts, Teddy Bridgewater is named the Broncos starter any day now, the number will rise to 8 because Drew Lock will become the latest backup.

Actually, another ex-Broncos starting quarterback is starting for another team, and one other recently was released.

Robert Ripley would exclaim: “Believe It Or Not!’’

Follow along closely:

Whathisname, who was the Broncos’ QB starter from 2012-2016, has been inducted into the Hall of Fame.

What’s happened to those starters who have followed him in Colorado?

WHO SHOULD BE THE DENVER BRONCOS’ STARTING QB?

Paxton Lynch, who started four games in 2016-17, is, get this, a reserve quarterback for the Saskatchewan Roughriders and hasn’t played a down yet.

Trevor Siemian, the Broncos’ starter for 24 games in 2016-17, is the Saints’ third-string quarterback.

Case Keenum, who played all 16 games in 2018, is No. 2 with the Browns.

Joe Flacco, who was the starter for the first eight games of 2019, is the second-team quarterback for the Eagles.

Brandon Allen, a starter for three games in ’19, is the Bengals’ reserve QB.

Jeff Driskel, who started one game last season, is one of the Texans’ myriad quarterbacks.

Brett Rypien, the starter against the Jets in 2020, is the Broncos’ scout team quarterback.

And that’s not counting Brock Osweiler, who retired in 2019 after starting for the Dolphins the year before.

Tim Tebow, who started 15 regular-season and playoff games in 2009-10 (and never was a starter again in the league), was cut by the Jaguars after participating in one exhibition as a tight end.

Phillip Lindsay, who is credited with being the starting quarterback against the Saints in 2020 in the “COVID QB game’’, is listed as the No. 1 running back for the Texans. Kendall Hinton, who actually played quarterback in that debacle, is destined to be back on the Broncos’ practice squad.

Two more ex-Broncos reserve quarterbacks are no longer around. Kyle Sloter, a 2016 marvel in Broncos exhibitions, was released by the Raiders earlier this year, and miscreant Chad Kelly, who was briefly an injury away from starting for the Broncos, was given a tryout by the Browns a few weeks ago, but failed.

Could Lock be next?

He has started 18 games the past two seasons. It’s possible, I suppose, Drew never starts one more in Denver.

Could he even become a career backup?

It seems that Vic Fangio is leaning, and about to fall over, in Bridgewater’s direction after the first two exhibitions and based on whatever criteria the coach is analyzing for his critical decision.

He who hesitates is lost Vic, and his offensive assistants haven’t found the final solution yet.

It was assumed that the choice would be made Monday or Tuesday prior to the last exhibition against the Rams. But the Broncos apparently are copying a process called stridulation — when crickets make a chirping noise.

Surely Fangio won’t carry this duel-to-the-depth into Saturday. We already know that the Rams won’t play anybody recognizable in the only exhibition @Mile High. What else can Vic learn about the quarterbacks facing a bunch of guys who will be wearing brown (not Browns) uniforms and driving UPS trucks?

What if Aaron Donald were playing?

If Lock loses, it won’t be because he flopped flat on his face in this quarterback-a-quarterback confrontation.

In two exhibitions, Lock completed 14 of 21 passes (66.7 percent) for 231 yards with two touchdowns, no interceptions, two sacks and 16.5 yards per attempt.

Bridgewater completed 16 of 19 passes for 179 yards (84.2 percent) for two touchdowns, no interceptions, no sacks and 11.2 yards per attempt.

In eight possessions Lock produced two touchdowns, three field goals and one nullified touchdown pass. In five possessions Bridgewater produced three touchdowns, one field goal and one nullified touchdown run.

Lock had the overall slight edge in practices, Bridgewater in the exhibitions.

As Fangio keeps saying, the quarterback competition is virtually even, although the coach has piled more praise on Bridgewater than Lock. Vic says he could have up to 19 days before The Decision. Ripley doesn’t believe that.

One will be the opening-game starter. The other starts as the backup.