The Candidates -
Do I really have to choose?? Sure, Micah Knorr could be a choice, simply because he was a Bronco the longest. That's no fun, however, but neither is trying to find any information about the other guys on the list.
Darrell Hackney is a fun choice, but I though I would go a different direction.
Thus, for me, when in doubt, revert back to the (not so) good ole' days in Broncos history, the 60's, and pick the place kicker that appeared in just 2 games for the Broncos, attempting a total of 5 FG's, converting only 2. That's right, some teams have names like Brett Favre that top their list of greats that wore #4. For the Broncos, it's almost as good....
The (not so)Greatest Bronco To Ever Wear #4 --
Rick Duncan, K - 1967
I know, you guys were hoping for a photo. Unfortunately his stay in Denver, and the AFL/NFL was too short for anyone to get a confirmed sighting. Such was football in Denver in the 60's.