So no sooner do I write a somewhat whimsical little post about the supposed Sports Illustrated cover jinx than in the next issue they have an offer for a book called "Sports Illustrated: The COVERS," which has every single cover of the magazine since 1954. And editor Terry McDonell in a little promotional letter even touches on the presumed jinx. "Not that being on the cover 22 times adversely affected Jack Nicklaus. Nor did Michael Jordan, who hit the cover trifecta by being photographed playing basketball, golf and baseball, suffer from his 49 appearances."
To some extent that doesn't necessarily disprove the jinx, which supposedly applies to the week ahead. Even great ones have bad games or bad weeks, so Nicklaus, Jordan et. al. might have had bad weeks after their SI covers. But how many out of 33 or 49? Probably not that many considering those two had precious few bad weeks, at least when it came to their sports.
I'm not the person to do the in-depth study -- though I suspect somebody out their is doing so even now. I rather doubt if it will p[rove the cover jinx theory, but it's still fun to contemplate.