Rigondeaux's flaws will work in Donaire's favor
Rigondeaux better bring something new to the table because the things he usually does in the ring won't work against Donaire. In fact, they will work in Donaire's favor.
-His right hand is very low and he likes to use it as a range finder, touch his opponent's gloves and bring it back low, he's pretty much asking to get countered over the top with a left hook.
-He's actually fairly easy to hit with right hand leads but even when he does duck the straight right hand, he gets low and then gets back up with his right hand by his waist. The straight right hand-left hook combination will be the key for Donaire in this fight, the right hand will either touch Rigo or will make him duck and open himself up for the left hook when his head goes back up.
-He doesn't jab much, he doesn't even throw that many punches, he's not that type of classical boxer. He's a patient counterpuncher who spends most of his time measuring his opponent. He doesn't open up until the timing and distance are perfect and when he does open up it's usually one shot at a time (unless his opponent is hurt). I don't see him winning many rounds that way against Donaire, Donaire will be throwing power shots and even if most of them are blocked his work will be enough to win most of the rounds. A couple clean left hands a round won't be enough for Rigo to win a decision.
-When he hurts his opponent he finally opens up and is very lethal BUT he relies to much on his left hand and throws it at a predictable rhythm. Even if he does hurt Donaire, I'm confident Donaire has the ability to time Rigondeaux's repetitious one-fisted attack and catch him with a deadly counter as he wounds up a left hand.
So in conclusion I would say that Rigondeaux is very skilled but in a mechanical kind of way, everything he does is calculated, not much variety but he's very efficient. Donaire on the other hand is highly instinctive, he can explode with power shots from both hands, change angles and throw punches on the move, he's very unorthodox and unpredictable. I think Donaire's explosiveness will disrupt Rigondeaux's rhythm and won't allow him to think as much as usual, that's why I got Donaire winning by KO or decision.