Because Rainsford sleeps in Zaroff's bed at the end of the story, what can be inferred?
In this tale of the eternally predatory nature of man, Sanger Rainsford finds himself in the ironic position of prey. Having been trailed and toyed with--"The general was saving him for another day's sport!" Rainsford realizes the first day as he crouches atop a branch in a tree above the Cossack--Rainsford learns the fear of pain and of death that the jaguars he hunts know. So, when he succeeds in stealthily entering the bedroom of Zaroff and the general congratulates him upon winning the game, an unsmiling Rainsford tells him with a hoarseness to his voice, "I am still a beast at bay."
Understanding the implication of Rainsford's words, the general bows deeply as does a man before dueling with swords.
"Splendid! One of us is to furnish a repast [meal] for the hounds. The other will sleep in this very excellent bed. On guard, Rainsford...."
He had never slept in a better bed, Rainsford decided.
Having alluded to himself as yet "a beast at bay," Rainsford indicates his intentions of attack. For him, the most dangerous of hunts is not over yet as he is cornered in Zaroff's room (hence the allusion to baying dogs) and has no choice but to fight. Because the prey fights for his life, he is extremely dangerous and often succeeds in overcoming his predator. Certainly, then, the reader may infer that Rainsford, who sleeps in Zaroff's bed according to the last line of the narrative, has won the game by killing General Zaroff.