In my experience when you have a big favorite as Nadal is on clay, him winning the match 2:0 will still be bad odds, him winning 2:1 would be good odds but that is all because you are playing that opponent will take one set. Now that means you are expecting sort of surprise but if that is a case you have much better bet that his opponent takes at least one set. Odds are usually quite close to that what you played and it is a bet which is much easier to win in the end. At least I am always taking that one or handicap when I am smelling a chance of upset. Never against Nadal on clay though
But who am I to preach, my super secure games for today was E. Frankfurt x2 and West Ham x2 and we all know how that went.
It was 4.34 for me. 2:0 wasn't even 2/1 boosted, I don't recall odds for Rublev taking a set -- maybe you're right in that case BUT the price boost was for picking a correct score, which is why I went for it =) Silly me!
Keep on preaching, man, I actually silently pay attention to what others do. Especially tennis, since I'm afraid I'm almost completely out of date with current forms.