Djokovic vs Federer
In 7 of their last 11 meetings both players have won a set during the match, and they way these 2 are playing, this easily could be a repeat of the stunning 5 sets match they played in the semifinal of the US Open in September. Both are looking so strong at the moment that it seems unlikely that one could hold the other in a firm grip over just 3 sets.
Djokovic won the aforementioned semifinal, but they have played each other 3 times since then, with Federer winning all 3, taking his lead to 13-6 in their total h2h. In these 11 wins Federer has won by at least 4 games on 10 occasions, so if you believe in Federer, it makes sense to take on this handicap-bet instead the straightforward Federer to win.
There is absolutely no reason why the outcome “no tie break” should pay as much as 2.25. There hasn’t been a single breaker in their last 6 meetings, and their last 12 meetings have only had one tie break to offer.