# Thread: Bishop and knight checkmate

1. And then there's KRR vs KRN, but how often would you see that in a game of any kind?

2. ## Maybe

Originally Posted by Kevin Bonham
At a high level of play KBN vs K happens about one game in 5000. I wonder if it is more or less likely than that or about the same at club level.
I have played 800 + tournament games since I started playing at age 11 and have only once had the KBN v K ending - last night, 139 moves and I was lucky to win it. See Dejan Antic coaching at Manly thread. (Too tired to paste the link in - someone else can! Ta!)

I have played 800 + tournament games since I started playing at age 11 and have only once had the KBN v K ending - last night, 139 moves and I was lucky to win it. See Dejan Antic coaching at Manly thread. (Too tired to paste the link in - someone else can! Ta!)
Done.

4. I mentioned above there was an instance of a GM failing to win KBN v K. This is it:

Kempinski,Robert (2498) - Epishin,Vladimir (2567) [E60]
Bundesliga 0001 Germany (5.3), 07.01.2001

 PGN Viewer

5. ## Wow!

Wow - 179 moves too!

6. ## Basic idea

Originally Posted by ggrayggray
In a top class game, the 'losing' player would resign before reaching the BN ending, because they 'know' that their opponent knows the winning patterns.

In lower class games, the 'losing' player will attempt to get a BN ending, in the hope that the 'winning' player doesnt know how to do it in less than 50 moves.
Yes!

For those who don't know (if any): The idea is not to check the King but to restrict the squares on which he can move until mate is given in the corner where the King is forced onto the Bishop's colour square. A good place for the N is diagonally behind the B so that between the 2 of them and the K they restrict the opposing K's moves severely. In my 139 move game I had to start with N on h7 (where it took P) so it took me many moves to achieve such things and several times his King had choices of which way to run...

My 139 moves was my longest ever tournament game too.

7. Thanks for the game, Kevin. That is truly amazing for a GM to not convert the win.

8. Originally Posted by Kevin Bonham
I mentioned above there was an instance of a GM failing to win KBN v K. This is it:

Kempinski,Robert (2498) - Epishin,Vladimir (2567) [E60]
Bundesliga 0001 Germany (5.3), 07.01.2001

 PGN Viewer

Good grief, this was a tedious game. White made several unforced errors around in the 50s losing Ps, then allowed two connected passed Ps on move 96. White was even cooperative in allowing his K to retreat to the last rank without a fight only 6 moves after the last capture. Then Black looked as though he was trying to mate White in the wrong corner, then he forgot the standard winning manoeuvre with 150... Nd5. He got it right on move 155, then White was remarkably cooperative with 151. Ka6 which loses quicker than Ka4. But Black then failed to find 156... Nb4+. Once again he tried in vain to win in the wrong corner, and wasn't even close when the 50 move rule was called — a few moves late at that.

9. Originally Posted by Jono
....and wasn't even close when the 50 move rule was called — a few moves late at that.
Black actually produced stalemate with 179....Nc8.

10. I never ever had to mate with B+N. But my king was mated twice: By Caoili and by Rujevic.

11. Originally Posted by Phil Bourke
Black actually produced stalemate with 179....Nc8.
So he did; I didn't even look that far.

Originally Posted by Phil Bourke
IIRC Botvinnik thought that GM who couldn't mate with BN should be stripped of his title. Another way of looking at it is that this knowledge is not a prerequisite for GM strength All the same, many other GMs will be very annoyed, knowing that many more people will play out the mate rather than resign because "surely a GM knows the technique so there is no point wasting his time and mine."

12. I think if I had KNB vs K I would play it out and hope for the best...it's too hard to work it out

13. Originally Posted by Miranda
I think if I had KNB vs K I would play it out and hope for the best...it's too hard to work it out
Of course in club chess I do not think anyone should resign when having the king. If for no other reason than to watch how the opponent actually does mate you in a real game.

14. Eclectic pointed out the following video explaining a different method to the Philidor technique explained in most endgame books: the Three Triangle method of Daniel Deletang. I don't know if it's quicker, but there are fewer rules to learn.

15. Originally Posted by Jono
Eclectic pointed out the following video explaining a different method to the Philidor technique explained in most endgame books: the Three Triangle method of Daniel Deletang. I don't know if it's quicker, but there are fewer rules to learn.
With the philidor system I have around a 30% success rate. After viewing this twice, I'm mating fritz every time, its really simple and I could do it at 10 seconds a move with ease.