“Take a tile known to both of you (if there is doubt, take one your oponent knows).”
I don’t understand the parenthetical comment: it seems to be saying “If you are not sure both of you know what a tile is, then choose a tile your opponent knows.” How could you know your opponent knows what a tile is but not be sure you know? Or maybe I’m just not understanding?
“Take a tile known to both of you (if there is doubt, take one your oponent knows).”
I don’t understand the parenthetical comment: it seems to be saying “If you are not sure both of you know what a tile is, then choose a tile your opponent knows.” How could you know your opponent knows what a tile is but not be sure you know? Or maybe I’m just not understanding?