The sequence started with McGregor revealing his MMA all-time pound-for-pound rankings, with Anderson Silva at No. 1 and himself at No. 2:
Conor McGregor @TheNotoriousMMA
GOAT THREAD. The array of finishes, across 2 divisions, with champion status in 1, Anderson Silva is No.1 MMA GOAT. My array of finishes, across 3 divisions, with champion status in 2, I’m No.2. If not tied 1. However still active, No.1 is fully secured by career end. And easily.
McGregor placed future UFC Hall of Famer and two-division champion Georges St-Pierre at third and current UFC light heavyweight champion Jon Jones a close fourth.
Diaz took umbrage toward McGregor's pound-for-pound GOAT rankings, referencing his submission win against McGregor at UFC 196 in March 2016 while touting his own candidacy (warning: tweets contain profanity):
Nathan Diaz @NateDiaz209
Smoked the #1 p4p and double champ know the real 🐐 when you see him And don’t for get I did it better and quicker than anyone else on the ground and sent him down with punches quicker than Mayweather did so fuck alll y’all rankings and know a real goat when you see me https://t.co/wHmDqVERmf
Khabib, the UFC's currently undefeated lightweight champion, then jumped into the mix and offered his two cents on McGregor's GOAT credentials:
The UFC's current pound-for-pound rankings have Jones at first, with Khabib following in second. McGregor sits in eighth. Diaz is not listed in the top 15.
Fight Matrix gives the all-time nod to St-Pierre, who finished his career with a 26-2 professional record and a 13-match winning streak that lasted an entire decade from 2007 to 2017.
His defeats came against Matt Hughes and Matt Serra, opponents that St-Pierre later defeated in rematches (Hughes twice via TKO and submission and Serra once by TKO).
In other words, St-Pierre beat every opponent he faced.
Jones is second on that list. McGregor's GOAT pick of Silva is fourth, and Khabib is 22nd.
Among the three fighters in the debate, Khabib defeated McGregor via fourth-round submission during their lightweight title match at UFC 229 in October 2018.
Diaz and McGregor have split two fights: the aforementioned Diaz submission win and a majority decision in favor of McGregor at UFC 202 in August 2016. Both Diaz-McGregor fights were welterweight bouts.
Diaz and Khabib have never met in the Octagon.