With the UFC rules, I have never seen another book use the rule below. Ties should be refunded since you are using 2 way lines in MMA.
The boxing bets that we offer are 3 way. You can bet on the draw.
Our MMA bets on the other hand are 2 way and we use the dead heat rule in case of a draw, so if you bet on the underdog and the match ends in a tie you will partially win and if your bet is on the favorite you will partially lose.
This is also true for other bets such as Half Time and Quarter money line bets in basketball where we use the dead heat rule in case of a tie.
We do not gain any advantage for using the dead heat rule over a push in case of a tie and we have not received any complaint about that to date.
If there would be sufficient demand from our clients we will consider changing it to a push.