This is a follow up to our first post on mirror play. In this second part we discuss how to beat mirror play.
Let’s start off by looking at some responses to mirroring. First player uses the standard opening and second player mirrors the first wall.
From here the first player wants to throw off the symmetry of the board right away. Let’s discuss two methods: leaving a gap and blocking the wall.
Leaving a gap
First player continues second player’s horizontal wall but with a gap left open. This move is a bit unintuitive because it seems to create more options for Green to get to the goal, when fewer options is desirable. Look again and you will see three gaps, all of which are difficult for Blue to close. None of the gaps are even and closest gap, the single space near the middle, will take at least 3 walls for Blue to close.
This is my favorite response to mirroring. Blue’s horizontal wall is obliterated and trying to save it will only waste walls. There is too much imbalance on the board for Blue to mirror. And the most difficult gap to close in Blue’s horizontal wall is closest to Green’s pawn.
While this is a strong response to mirroring, it does also make the board a bit crazy to start. Take your time and study your opponent’s response carefully.
Blocking the wall
Block second player’s ability to extend their horizontal wall. If Blue continues to mirror Green’s moves soon we will have a box in the middle with two exits. You might notice that this is similar to the center box that was getting Green in trouble when we started looking at mirror play.
The important difference is that this box is turned on it’s side and there’s more room in the middle for Green to work with. With Green’s move to follow there are plenty of options to take advantage of Blue’s early mirror.
Be careful if you get to this point in the game. You don’t want to get closed out of the box going in the wrong direction. Play a wall that can close Blue’s side of the box in one more move.
Mirror play can be frustrating if you don’t know how to stop it. The two openings in this post should give you the tools to start with, but remember that even the best opening is worthless with out sold end-game play in Quoridor.
Screen shots are from Vielen Games version of Quoridor on Android. Download it today and look for Kevin!