[iamnotacrook]

Blindfold chess? Just search for it on youtube. Most GMs can do this easily. Some simultaneously play 10+ sighted players whilst blindfold. Even when not blindfolded they often look away from the board whilst calculating so that the current state of the board doesn't distract them.

[busyant]

It's not exactly blindfold. With blindfold, the blind player still knows the opponent's moves...They just don't have the luxury of being able to _look_ at the state of the board (although top-tier chess players don't need that luxury).

This is a little different, but I think/speculate they would still have enough heuristic knowledge to crush most people.