Mined squares

Why should I learn it?

Corollary to the principle of opposition and outflanking is that of mined squares, only one of the different aspects of another concept—key squares—that will be discussed below. It’s important to understand it because it tells you what to avoid, and how to draw your opponent into a trap. Mined squares often modify the simple concept of opposition, so that you should be aware of any such squares present at all times.

When do I use it?

Most often in positions where opposing pawns are locked (i.e., blocking each other) and the Kings fight for access to them. In these situations you must avoid stepping on a mined square, which will ensure your opponent (if he gets it right) can find his way to the pawn chain under favorable circumstances. On the other side of the coin, your opposition calculations will naturally be aimed at leading the opponent to step himself on one of the mined squares.

Link to Practice Problems

Mined squares problem #1

Step-by-Step Guide on Mined squares

What is a mined square? From the term itself, it is a dangerous square for the king to step onto. In the diagram, the mined squares for White are a4 and c4. If the White king moves into any of those, the Black king would then respond with Kb6, snatching our b5 pawn on the next move.

In order to defuse those mined squares, you have to use your extra space — since the black King also has to keep an eye on your b-pawns — in order to go around and enter the c4 square only when black no longer has access to b6. Then maneuver in a similar fashion to the last instance, sacrificing one pawn in order to reach a winning position.

1. Kc3

The only move that makes progress. This lets the White king to jump into d4 or c4 depending on Black’s next move. If the Black king steps on b6 then the c4 square is no longer mined.

…Ka7

Preparing to jump into b6 in case the White king moves with 2. Kc4

White does not fall for the trap and prepares to jump into c4 if Black moves with Kb6.

…Kb6

Preventing the White king from going into c5 while threatening to take the pawn. However, take note that thanks to the b4 pawn, the Black king is unable to step on a5 and c5.

After Kb6, there is only one move to protect the b5 pawn and to prevent a draw.

The c4 square is no longer a mined square because the opposing king could not take any pawn on its next move.

…Kc7

The Black king goes to c7 to gain access to d6 and block off the White king. Thankfully for White, it is their move.

Preventing the Black king from going into b6 or d6.

…Kb7

Blocking the pawns’ path and looking to move into b6 once again if the White king goes away.

With this move, Black is forced to pick between the 8th rank or a6 to retreat to.

…Ka6

Black tries to trick White into a draw. After this move, the only square Black could retreat to is b7.

The only winning move, sacrificing a pawn to gain a positional advantage.

(6. b5+? Kb7 7. Kc4 Kxb6 would be an easy draw for black.)

(6. Kc6?? Is stalemate)

…Kxb7

Eliminating one of the opponent’s soldiers but White now has complete control of the situation.

(6. …Ka7 would also be losing due to 7. Kc6 Kb8 8. b5 Ka7 9. b8=Q+ Kxb8 10. Kb6 Ka8 11. Ka6 Kb8 12. b5 Ka8 13. b6 Kb8 14. b7 Kc7 15. Ka7 Kd7 16. b8=Q)

Gaining positional advantage and staying in front of the pawn.

…Ka7

Sticking close to the edge to raise the chances of stalemate.

(7. …Kc7 is met by 8. Ka6)

Freeing the pawn’s path while making sure to have the White king control more ground.

…Ka8

Still sticking to the edge, hoping for a draw. However, White could easily avoid that.

The pawn begins its march.

(9. Kb6 is also winning, trying to limit Black’s activity into the 8th rank.)

…Ka7

Still hoping to trick White into a draw with 10. b6+? Kb8.

The only winning move. This move also makes it so that the only square Black could retreat to is a8.

…Ka8

The only move.

Although forced, this opens up a chance for Black to prevent a loss. After Ka8, the only square left for the Black king to retreat to is a7. If White advances the pawn, taking away the a7 square from Black, then the game ends with a stalemate.