KBN versus K

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Arshad Ali
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KBN versus K

Post by Arshad Ali » Fri Mar 29, 2013 8:46 pm

Is there anyone here who can't checkmate with K+B+N versus K? Is there anyone who can? And for those who can: Do you employ some algorithm, some sequence of steps or is it "by feel," where the K+B+N gradually force the K into the wrong corner and from there into the right corner to administer the coup de grace?

Paul Dargan
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Re: KBN versus K

Post by Paul Dargan » Fri Mar 29, 2013 9:19 pm

There's a much simpler method than the W-shape pattern normally taught using diminishing triangles, that makes much more intuitive sense - akin to electric fences and rooks, etc...

Arshad Ali
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Re: KBN versus K

Post by Arshad Ali » Fri Mar 29, 2013 9:32 pm

Paul Dargan wrote:There's a much simpler method than the W-shape pattern normally taught using diminishing triangles, that makes much more intuitive sense - akin to electric fences and rooks, etc...
Is this a carefully guarded secret passed on only to a chosen few?

Michael Bennett
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Re: KBN versus K

Post by Michael Bennett » Fri Mar 29, 2013 9:35 pm

Paul Dargan wrote:There's a much simpler method than the W-shape pattern normally taught using diminishing triangles, that makes much more intuitive sense - akin to electric fences and rooks, etc...
This video covers that way (the method of 'three triangles'):
http://www.youtube.com/watch?v=PWZ7h2yrJME
Michael Bennett
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Reg Clucas
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Re: KBN versus K

Post by Reg Clucas » Fri Mar 29, 2013 9:59 pm

I've learned how to do this, but have never had it in an actual game. I can win it against my computer on its highest strength setting. However I'm still working on 2 knights v pawn......

Paul Dargan
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Re: KBN versus K

Post by Paul Dargan » Fri Mar 29, 2013 10:07 pm

Sorry - there was a really good video on you tube - but I cant find it anymore... the link posted sint the one I'd seen before ... but describes the same method.

Jonathan Bryant
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Re: KBN versus K

Post by Jonathan Bryant » Fri Mar 29, 2013 10:22 pm

I learned to do it one night when I couldn't sleep. I heard of the triangle method later but never bothered to learn that because actually the traditional method isn't that hard to retain when you realise it comes down to remembering three key positions.

I've never had it in a game. If I met an opponent in my normal range who could do it I'd count myself unlucky.


PS: I don't believe 'by feel' is possible for KBN v K. I think you've got to know how to do it or you'll never find it over the board. Certainly there are documented cases of GMs - I'm looking at *you* Mr Epishin - who've not managed to win it.

David Blower
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Re: KBN versus K

Post by David Blower » Fri Mar 29, 2013 11:40 pm

This is something I do know how to do. :mrgreen:

However in all my life I have never had to do it.

Arshad Ali
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Re: KBN versus K

Post by Arshad Ali » Sat Mar 30, 2013 1:59 am

David Blower wrote:This is something I do know how to do. :mrgreen:

However in all my life I have never had to do it.
Doesn't matter -- you can put it on your resume.

I can force the king into the wrong corner by "feel." But when it comes to getting the king from the wrong corner into the right one, there's one tricky position where it looks like the king is breaking out and one has to know what to do then.

David Blower
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Re: KBN versus K

Post by David Blower » Sat Mar 30, 2013 2:38 am

Arshad Ali wrote:
David Blower wrote:This is something I do know how to do. :mrgreen:

However in all my life I have never had to do it.
Doesn't matter -- you can put it on your resume.
Thanks. :mrgreen:

For what its worth I always use the triangle method myself. Its a very structured way, and it even allows a few mistakes, but as the bishop and knight form a solid wall the king can't escape. This may not be the best way, or take the fewest moves, but its less than 50 moves and allows a more simple win I think.

The "W" method for me, there seems to be too much thinking about it.

Dan O'Dowd
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Re: KBN versus K

Post by Dan O'Dowd » Sat Mar 30, 2013 3:52 am

Arshad Ali wrote:
David Blower wrote:This is something I do know how to do. :mrgreen:

However in all my life I have never had to do it.
Doesn't matter -- you can put it on your resume.

I can force the king into the wrong corner by "feel." But when it comes to getting the king from the wrong corner into the right one, there's one tricky position where it looks like the king is breaking out and one has to know what to do then.
Yeah, that's when the motif that the Bishop/Knight if separated by five squares dominate and form the cage isn't it, after the enemy King goes to the sixth temporarily.

I learned KBN v K back in about 2007, I practice it every so often but I'm confident that I could do it over the board with a reasonable amount of time remaining. I suppose I'm abnormal for a good club player in having a strong interest in theoretical and practical endgames though as opposed to finding other means of enhancing my play.

Ray Sayers

Re: KBN versus K

Post by Ray Sayers » Sat Mar 30, 2013 7:49 am

I love this triangle method! Never seen it before but it looks pretty simple (if a little more long winded) compared to the W method.

Useful in a time scramble!

I practice the W once in a while against Rybka though to be honest I have NEVER had to do it in a competitive game.

Paul Bielby
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Re: KBN versus K

Post by Paul Bielby » Sat Mar 30, 2013 9:06 am

I have had this position 3 times in my (admittedly rather long) chess career. Twice with KBN and once defending with the K. I can't remember the circumstances of the first time I had to try to win it sometime in the '50s. I hadn't a clue and agreed to a draw, assuming it was impossible.

The second time was in a Durham County championship game (v.Alan Claremont, circa 1970). Here I was able to adjourn, went back home and looked it up in my Staunton Handbook (1875 edition) and was able to come back to win it a week later. Unfair, perhaps, but in those days adjourments were the rule.

On the third occasion I was Black against a 15-year old Jonathan Rowson. The future GM couldn't win it and 50 moves later we drew. I was then able to teach him how to do it and I'm delighted to say that he came up to me a couple of years later to tell me that he'd won it in another match. As a coach I'm proud to be able to claim I've taught a GM (Should this be on the bragging section of the forum?)

More seriously, as a coach, I often use this ending as an example for some of my better students. I find it a useful illustration of how to use three pieces working together to an end.

Jonathan Bryant
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Re: KBN versus K

Post by Jonathan Bryant » Sat Mar 30, 2013 9:10 am

Ray Sayers wrote: I practice the W once in a while against Rybka ....
One of the things about KBN v K is that although it's impossible to find if you don't know what you're doing, it's really not that hard if you do. The most difficult thing about learning it is doing the 'revision' every now and then to keep the method in mind.

The trouble with practicing against a computer, in my experience, is that they just shunt the king to the wrong corner straight away. No doubt this is 'correct' in that it delays mate the longest, it's not at all how a real person would play.

Nick Thomas
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Re: KBN versus K

Post by Nick Thomas » Sat Mar 30, 2013 10:08 am

I had it in the 2011 4NCL rapidplay with just the 5 second increments remaining. It's a little more difficult under pressure but I did manage it. Strangely enough someone else had it at the same event (can't remember who) and failed to find the mate. Everyone was a bit confused about whether they could just keep trying ad infinitum given that the 50 move rule was hard to impose without an arbiter counting (and I don't think the arbiters were taking much interest - apologies if I'm wrong about that last point).

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