There's an Alan Moore short story early in his career that he declined to have reprinted because he realized after he'd written it that he'd inadvertently ripped off Lafferty. The story concerns a man who builds a machine that lets him go slightly back in time, which he uses to his advantage at a casino, but who is then thwarted by a coat attendant with a "probability manipulator." I'd love to track down the original Lafferty story. Does it ring a bell?
Answered below, but wanted to make sure all the content was posted. Do you recall which Moore story that was? Would be interested in seeing that influence, however unintended.