When UFC decides to make a trilogy out of a feud, usually it requires that both fighters have each won one match and at least one of them had a close result.
In the case of Benson Henderson and Frankie Edgar, the fights have been so close that even despite Henderson's two wins, this feud needs to become a trilogy.
Henderson has defeated Edgar twice this year. The first time was at UFC 144, with Henderson ultimately prevailing in a competitive bout. The judges sided with Henderson, and he was awarded a unanimous decision victory and the UFC lightweight championship.
At UFC 150, things were much closer between the two. In fact, watching the fight, it did appear that Edgar did more to warrant a decision victory. Henderson did win the first round—that much was obvious.
After that, it was anyone's guess. It never felt like one fighter had a decided advantage over the other, so if you want to make a case for Henderson winning, there is certainly not much of an argument to be made against that.
But when the scores were announced—with Henderson winning a split decision—Edgar exploded with rage because he felt that he did enough to win. Again, it was so close that no one could argue that what the judges said was wrong.
Yet when you have two fighters who are so evenly matched, and they have two fights that end up being victories for one person by the slimmest of margins, the temptation is always there to settle any debate once and for all.
Fans love trilogies, even if they aren't between the biggest-name fighters in the sport. There is an easy story to tell in order to market a third fight to the fans. And, most importantly, there is a legitimate reason to do a third fight.
Edgar is at a point right now where he will probably have to win a fight before he gets a title fight, but when he does, Dana White can't shy away from making the right match for the sport and the fighters just because it has happened twice before.