MDF: 71% means that we have to defend this river 7 out of 10 times we reach this instance. In this case the existing possibilities for villain are: Boat, flush, trips, double pairs and of course pure bluff = 100%
If we make hero calls with double pairs, trips, flushes and lows scales of boats, we are exceeding this number by 10% (4/5 = 80%). This means that we must look for the highest scale of each hand that we call, to reduce this margin and isolate ourselves with less amount of strong combinations of the V range.
But fundamentally we must adjust the quality of our most vulnerable bluff catchers, such as double pairs.
For example: in this hand it is not desirable on the river to block QX combos of rank V with double pairs for hero. Because in this way we are reducing the line of 2 pairs in the V range. But if we call on the river with 2 pairs that include a Q, we should do it with the best possible pairs, which in this case is Q-9. Because it is better to block 5 Q-9 combos and leave 6 Q-6 combos in the V range than the other way around. (If we call with Q-6 we block 5 Q-6 combos and leave 6 Q-9 combos in the V range, but this It is not the most desirable since we lose against them). And so on with each hand we call on the river, so that our defense is as efficient as possible, IMO.