Many times it simply comes down to which team is the healthiest. Russell badly sprained his ankle in the '58 finals against the Hawks. The Celtics lost. In '73 with the Celtics the best team in the league, Havlicek hurt his shoulder in the playoffs, and the Knicks (fourth best team in the league) won the title. The Lakers, who easily defeated the Knicks in the finals the previous year, had West suffering from hamstring pulls to both legs in the '73 finals. The Lakers won the first game, West scored over 30 points, but lost the next four all by close scores with West severely hobbled.
The most famous or notable case of Wilt's bad luck is when he badly twisted his knee with six minutes to go in the '69 finals. He tried to play on it but had to leave for a few minutes to get it worked on. Then Van Breda Kolff, who hated Wilt, refused to put him back in the game when Wilt asked to go back in. The Lakers lost the seventh and final game by two points. There were quite a few other instances of injuries to Wilt or his teammates or lucky plays by the Celtics in the last moments. Wilt is the unluckiest great player in history.
Wilt doesn’t get enough respect as a plausible greatest player of all time. I’d pick him over Jordan.