Pavel, the Grail seems to be located in the 4 cells at the intersection of the diagonals, so finding it on the third attempt isn't luck, but rather the opposite – it's skill. And there's no question of looking at the map.
I admit, I'm not familiar with the technique of finding the Grail, but I might change my opinion after learning about it.
At the same time, if players have mastered this technique and are allowed to place the Grail, won't the game simply come down to who can place the Grail faster?
