There's a few reasons he may have been a dud... Did you feed him like the rest of your clan? Where is he located?
If he was fed like all the rest and in the tent and still didn't produce I wouldn't breed with him personally...
When I choose a male I look for pretty much the same in him as the mother. Vigor, Smell, structure, virility, etc. And if you are breeding for stability then you want to literally match him with the female. Structure/Pheno wise...
I have just started reading The Breeders Bible... So I also have much to learn. But from where I have my own crosses right now that's how I've gotten them to this point. But those guidelines I mentioned...
Hope this helps...