The odds of the favorite losing 8 times in a 12-fight card, given that the favorite wins ~63% of the time, is approximately 0.0274, or about 2.74%
#ufc297 set history for a UFC event with 8 dogs
#UFC247 was 5-7
#ufc226 was 3-7
#ufc215 was 4-7
#mathbabble
If you went 6-6 tonight, you were top 5%
only 2 UFC fight night cards were worse.
The worse was
UFC Fight Night - Mir vs. Bigfoot
Porto Alegre, Brazil; 22nd Feb 2015
Favourite wins: 1
Underdog wins: 10