In this week’s article, we’re going to look at the most difficult checkmate for the beginner to master, mate involving Knight, Bishop and King versus lone King. This mate proves to be difficult even for “improvers” because it requires forcing the opposition King to a specific corner square using two minor pieces that move in very different ways. In last week’s article, we learned how to use a pair of Bishops with our King supporting them to deliver checkmate. Because each Bishop can only control one color square (either light or dark), as opposed to Rooks who can control both colored squares simultaneously, they have to work in closer coordination with one another and their King. On the plus side, the two Bishops move identically (diagonally) so pushing the opposition King towards the mating square is easier than in the case of the Knight and Bishop.
With the Knight and Bishop duo, it’s all about herding the opposition King to a corner square that the Bishop can control. Yes, I said herding! I’ve watch a large number of videos and read through numerous books that explain this idea of forcing the King being mated to the mating square using a triangulation system. As a chess instructor and coach, I’m well versed in this checkmate and even I was left a bit confused trying to determine just how the triangulation system worked. In reality, it makes perfect sense to more experienced players but the beginner might get confused so I decided to simplify the idea.
Think of the opposition King as a sheep. Your Knight, Bishop and King are the sheep herders. Their goal is to herd the stray sheep back into it’s pen, in this case the mating square. Your job is to herd the stray sheep, I mean King, back to the pen with as little fuss and muss as possible. Take a look at the example below:
This is a simplified position compared to example two but I present it first because it helps to clarify the key points you need to understand in order to checkmate in this way.
The first point to consider is that the opposition King must be driven into a corner because the checkmate can only occur if the King is literally cornered! Since there are four corners on a chessboard you have to determine which one is the correct corner. The good news is that you have a choice of two. Which two? It depends on the color of the squares your Bishop controls. In the above example, we have a Bishop that controls the dark squares. Therefore, the King has to be driven onto a dark colored corner square. Since you have two, the a1 and h8 squares, how do you decide? The answer is simple if the opposition King is closer to one of the two. You drive the King to the color square controlled by the Bishop that is closest to your Knight and Bishop duo. If equidistant, the choice is yours!
In our first example, the King has been driven towards the h8 square so that’s our target mating square. We start with 1. Nf5. Of course, the black King would like to run in the opposite direction of the h8 square but can’t because of the Bishop on b4, which controls the f8 square, so black is forced to play 1…Kh8. This kind of endgame position requires precise coordination between the Knight, Bishop and King. Failure to do so will allow the enemy King to escape and you’ll have to herd the King back to its pen all over again. You’ll see how hard herding is in our longer example.
White plays 2. Be7 which maintains control of the f8 square while lining it up with the f6 square. Black responds with his only legal move, 2…Kg8. White’s pieces are slowly moving in and surrounding the black King. White checks with 3. Nh6+ which forces the black King back to h8 with 3…Kh8. You should always examine potential escape squares for black before making a move in this type of position because giving the opposition King a chance to run away will force you to start all over again. You’ll see how horrible this can be shortly.
Looking at the position, we can see the the white King creates a barrier on g7 and h7. Our trusty Knight keeps the black King off of the g8 square. Now all we have to do is deliver the final blow with 4. Bf6# and it’s game over!
This example is the end result of a series of moves that drive the opposition King into the corner. However, as we’re about to see, the real challenge is simply getting that King into the corner. Let’s introduce a new key point, the idea of where you don’t want the enemy King to go. As a herder, you don’t want your sheep running behind you because you’ll have to turn around and start herding them back towards the pen. The same holds true in this type of position. You have to carefully and methodically herd the King to the target square.
In the above example, we have a dark squared Bishop which means we have to get the opposition King into a dark corner square, either a1 or h8. This means herding the King into the correct corner. Again, you can think of the black King as a sheep and the three white pieces as the sheep herders. As the commander of the white army, your job is to carefully control key squares the black King can use for his escape. You have to think in terms of where you don’t want the opposition King to go!
The Bishop on e3 controls the a7 square and the white King controls the b7 square so we start with 1. Nc7+. Note that the Knight on c7 is protected by the white King. You have to make sure that your pieces are protected at all times since losing one of your two minor pieces will lead to a draw! Black is forced to play 1…Kb8. The dark squared Bishop must maintain control of the a7 square, so as the black King doesn’t make a run towards freedom via that square, which is why white plays 2. Bb6, tightening white’s control of important territory. Black plays 2…Kc8, being pushed towards the mating square, h8. With 3. Ba7, white keeps the black King from going to b8, so the black King moves to d8 (3…Kd8). With 4. Nd5, white controls the e7 square and black moves the King to e8 with 4…Ke8. Now, white’s King enters the battle with 5. Kd6. This is where things get a bit difficult because the black King makes a run for freedom with 5…Kf7. In this type of checkmate, white will have to deal with the opposition King heading away from the corner towards the center where it will be difficult to corral him back towards the mating square. Therefore, you have to carefully consider your minor piece placement!
To the beginner, the move 6. Ne7 may seem to give the opposition King more freedom to escape. However, the Knight covers the squares f5 and g6 which could be used as flight squares by black. The black King moves to f6 with 6…Kf6 and rather than check the King with 7. Bd4, white instead plays 7. Be3, again looking to cut off the black King rather than make a useless check. From e3, the Bishop covers the g5 square and black is pushed back with 7…Kf7. White now brings his Bishop to g5 with 8. Bg5, tightening the noose around the black King. Black plays 8…Ke8. Here white must move the Knight so the Bishop has unblocked control of the d8 square, so 9. Ng6 is played. Now black must move towards the mating square with 9…Kf7. While it seems that white’s Knight is now under attack, the simple 10. Ne5+ puts an end to that.
Of course, black is going to do everything humanly possible to avoid h8 so he plays 10…Ke8. Again, the white King steps in with 11. Kc7, keeping the black King off of the d8 square. It’s important to use the King’s ability to control key squares at the right time and this is the right time!
With 11…Kf8, white uses his King to once more push the black King towards it’s sticky end with 12. Kd7. Use of the King is critical in endgame play! Black makes another feeble attempt to break free with 12…Kg7 and white meets this with 13. Ke7. The King is a powerful weapon in the endgame! The black King moves to g8 with 13…Kg8 and white moves his Bishop, 14. Bh6. This last move helps control squares the black King wants use as an escape route. With 14…Kh7, black tries to attack the Bishop but the Bishop moves to f8, 15. Bf8, and maintains control of two key squares, g7 and h6. After 15…Kg8, the white Knight makes a move most beginners don’t understand because the Knight appears to be moving away from the action, 16. Ng4. Unlike the Bishop, the Knight often has to make extra moves in order to get to a key square, as we will see in a few moves.
Black plays 16…Kh7, again trying to escape. On move 17, rather than deliver check with the Knight (Nf6 which would allow the black King to move to g6), white moves his King to f7 with 17. Kf7, using the power of King opposition. Black plays 17…Kh8 and white follows with 18. Bg7+. This is a well thought out move because the black King is forced to play 18…Kh7. Now we see why the white Knight moved to g4, so it could eventually move to f6 which delivers mate with 19. Nf6#!
The key ideas to keep in mind with this type of checkmate are pushing the opposition King to a corner square that your Bishop can control, moving your pieces in a coordinated fashion that keeps the opposition King off of specific squares and using your King actively. I have my students play through this mate until they can do it without too much effort. This means they may play through the position twenty plus times. I highly suggest you play through this position every chance you get until you know it. It may not come up much in your games but when it does and you’re not prepared, you’ll lose the game. Even though it doesn’t come up a great deal, it will teach you volumes about piece coordination. Break out a chess board and get cracking. Here’s a game to enjoy until next week!