First off, some people consider ''GOAT'' as someone who would win an open weight tournament during their ''prime'' (whatever that means), I believe that to be wrong simply because a guy like Mitrione isn't better than MM, yet would win a fight 99% of the time.
The same names are brought up again and again: MM, DC, GSP, Jones, Silva, Fedor and Aldo So we will go with those 7. Anyone who believes anyone other than those 7 deserves GOAT status should not be taken seriously about anything MMA-related.
Now the most obvious part is out of the way, let's look at what makes someone resume ''GOAT'' worthy:
1) Finish %
2) Win %
3) Title reign (defenses, multiple titles)
4) Quality of opponents
5) Use of PEDs
FINISH % (based on the number of finishes divided by number of wins)
1a) Silva - 76%
1b) Fedor - 76%
3) Jones - 70%
4) DC - 68%
5) Aldo - 64%
6) MM - 59%
7) GSP - 54%
WIN % (based on the numbers of wins divided by total fights)
1) GSP - 93%
2a) Jones - 92%
2b) DC - 92%
4) Aldo - 88%
5) MM - 87%
6) Fedor 84%
7) Silva - 79%
Tile Reign (based on title wins in dif weight classes, total number of defenses, consecutive defenses, multiple weight titles)
1) GSP (9 WW defenses, MW champ, 16-2 in title fights)
2) DC (3 LHW defenses, 1 HW defense, LHW and HW champ 7-1-1 in title fights)
3) MM (11 defenses, 13-2-1 in title fights)
4) Silva (10 defenses, 11-2 in title fights)
5a) Jones (8 defenses, 11-0-1 in title fights)
5b) Aldo (9 defenses including WEC, 11-3 in title fights)
7) Fedor (3 pride HW defenses, 2 WAMMA HW defenses, no UFC titles)
Quality of opponents (based on opponents records and win streaks at the time of the fights, top 5 wins and top 10 wins)
1) GSP (most top 5 wins, most top 10wins, stopped insane streaks such as Fitch, Shields, etc.)
2) Jones (beat tons of former champs and legends of the sport)
3a) DC (decent lineup of opponents)
3b) Aldo (similar to DC)
5) Silva (MW was fairly weak at the time of the reign, no Romero, Rockold, etc.)
7a) MM (can barely name 5 note worthy opponents)
7b) Fedor (a lot of good wins and former UFC champs, but also a lot of freak shows)
Use of PEDs
1a) MM
1b) GSP
1c) DC
1d) Fedor
1e) Aldo
7a) Silva (caught on multiple occasions)
7b) Jones (nothing more needs to be said at this point)
Now let's look at this data with a point based system:
Rank 1 - 6 points
Rank 2 - 5 points
Rank 3 - 4 points
Rank 4 - 3 points
Rank 5 - 2 points
Rank 6 - 1 point
Rank 7 - 0 point
The results are the following:
1) GSP - 24 points
2) DC - 23 points
3a) Aldo - 17 points
3b) Jones - 17 points
5a) MM - 13 points
5b) Fedor - 13 points
7) Silva - 11 points
This list is as objective as it can get and a great representation of a real best P4P in history, in the accurate order.
Future contenders: Khabib, Holloway and Woodley.