Heading into his fight with Fabricio Werdum on Saturday, the 29-year-old Russian Alexander Volkov had been to every corner of hell. He’d stood in against human drudge-and-doom hammers like Cheick Kongo and Roy Nelson, losing the former (and winning the latter) by existential decision. He toured the U.S. like a two-bit comedian, visiting the kind of towns that advertise HBO in the hotel rooms....