According to the current official UFC rankings, the top-five pound-for-pound fighters in the UFC are Jon Jones, Jose Aldo, Cain Velasquez, Demetrious Johnson and Chris Weidman, in that order. Jones at No. 1 is all but indisputable, and Aldo at No. 2 is really the only other option. Beyond that, the rest of the rankings are up for debate.
No. 3 is the heavyweight champion, Cain Velasquez. Cain is a two-time UFC heavyweight champion and has defended his title a total of two times. He is 13-1, with 11 finishes by (T)KO and only two decisions. His one loss was a 64-second knockout loss to Junior dos Santos to lose the title his first time.
Following the loss to dos Santos, Cain rattled off four straight wins en route to getting his belt back. The first fight was a TKO at 3:36 of the first round against Antonio Silva, which earned Cain another crack at the title, and a rematch against dos Santos.
Cain absolutely dominated the fight, earning a unanimous decision with scores of 50-45, 50-44 and 50-43. He has defended his title twice in his current reign, first with another first-round TKO over Antonio Silva, and then with a fifth-round TKO over dos Santos in their third fight.
He is undoubtedly one of the top-five fighters in the UFC, but should Velasquez really be ranked above the flyweight champion, No. 4-ranked, Demetrious Johnson?
Johnson is undefeated since having dropped to flyweight. His first fight was a majority draw against Ian McCall, and his second was a unanimous decision over McCall in their rematch. Johnson's next fight came against Joseph Benavidez for the inaugural flyweight title. Johnson won by split decision (48-47, 47-48, 49-46), and began his dominant title reign.
In his first defense, Johnson defeated The Ultimate Fighter 14 bantamweight winner, John Dodson by unanimous decision with scores of 49-46, 48-47 and 48-47. Dodson's loss to Johnson is his only loss since 2010. In addition, their fight won Fight of the Night.
Johnson scored his first UFC finish in his next defense, as he earned Submission of the Night for his fifth-round armbar over John Moraga, in a fight that Johnson had dominated entirely.
For Johnson's third title defense, he again faced off against Joseph Benavidez. This fight went very differently than the first, as Johnson scored a knockout with a huge right hand at just 2:08 of the first round.
Johnson's most recent fight—his fourth title defense—came against Ali Bagautinov, who had been on an 11-fight win streak with seven finishes. Johnson won a unanimous decision with scores of 50-45 on all three scorecards. As if that wasn't impressive enough, Bagautinov later failed a post-fight drug test for EPO. For those who may not know, EPO is a hormone that controls production of red-blood cells.
Johnson has defended his title a total of four times. In a division not known for finishes, Johnson has scored a finish in two of his defenses over top competitors. He has also earned wins over all of the top five fighters in the division.
Velasquez has only defended his title twice. He failed to defend the title his first time with the belt, and he lost it after being knocked out in just 64 seconds.
In addition, his last five fights have come against the same two opponents, and those are the only two opponents in the top 15 that he has beaten.
At the end of the day, Demetrious Johnson deserves to be the No. 3 pound-for-pound fighter in the world. With a win over Chris Cariaso at UFC 178, Johnson might even be able to make a case to be No. 2.