#10 truly blind meant "biologically unable to see", and it was a hypothetical question to casually explore whether a truly blind chess player may have an advantage in blindfold chess, or not. If it helps, imagine them as IMs, as I'm sure there are a few out there.
For example, as many truly blind chess players tend to move their hands over the board to gain a mental picture of how the board is, they may exercise their spatial memory abilities more than a player who can simply see the board, which might create an advantage in a game of blindfold chess.
For example, as many truly blind chess players tend to move their hands over the board to gain a mental picture of how the board is, they may exercise their spatial memory abilities more than a player who can simply see the board, which might create an advantage in a game of blindfold chess.