Very tough spot. Very suspicious situation for bluffs given your positions, especially since you know that he 's a good player. He can have anything literally.
I think we need to give him the credit of a good play and move on to the next hand.
- Why would a skilled professional player donk on this turn?
1) Maybe for value, because he has a made hand and at the same time he knows that this board has nothing to do with your range and you will check because you know that it hits his range xD.
2) Maaaaaybe he tries to see the river in the price he wants in case he goes for the flush. If he hits or miss he goes for the last bet (value or bluff) His bet maybe will even win the pot right here.
3)He bullies you xD. Has decided to bluff you starting from the turn.
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