For betting purposes, the tiebreak only counts as one game for total games and point spreads.
Doubles matches (including mixed doubles) are usually best of three sets, with a Super Tiebreak to ten points played if the score reaches a set all. The winner of the Super Tiebreak will only be considered to have won one game when grading for total games and point spreads. This happens in most tournaments, except grand slams. In grand slams, they play a normal third set.