K+B+N vs K checkmate

[Alexander Hardwick]

Hi all,

The topic of K+B+N vs K checkmates came up recently in a different thread (the one about whether or not it is rude to resign, General Chat). I thought I'd give it a thread of its own, just to see how many people have actually ended up in such a situation in a tournament game. I have heard that it is a rare situation to end up in. I for one have never had to display my (non-existent) K+B+N vs K checkmating skills. Come to think of it, I haven't ever had to play out a K+2B vs K ending either.

Best wishes,

Alexander.

[Paul Bielby]

I have played Jonathan Rowson twice, both times well before he became a GM. He must have been about 13 the first time when I succeeded in beating him; a few years later he established a winning game against me with B, N + P against my R. In desperation I sacrificed my R for his P and left him to see if he could mate me with K, B + N. He had to do this fairly quickly but failed to do so. Game drawn! I then taught him how to do it. A year later I met him again and he said he'd reached the same endgame again and won it!! So I can claim to have done something for one GMs education!

[Alex Holowczak]

I only ever have to do it when someone exclaims, "You can't mate with a Bishop and Knight!"

I always do it the triangle way, which relies on your pieces being orientated such that the opposing King is in the triangle, and able to quickly get into the position they need to be in. Seemed the easiest way to do it to me, though it's more time consuming.

[Peter Shaw]

I had to do it in about half a minute earlier this year with about a dozen people watching and managed it with a few seconds to spare. One of my proudest chess moments! The starting position was quite favourable as my pieces were already reasonably well co-ordinated.

I've had the wrong end of it once about ten years ago, we both had about a minute and a half left but he quickly stalemated me.

[James Pratt]

In the infant Philip Rossiter mated JJ Cox with B & N without hestitation at Manor Tyres in the days of yore.

Playing in a county match, I was obliged to try same, my opponent having tacken advice from a spectator to test me.

failed ..!

[Jonathan Rogers]

This was perhaps one of my finest moments: I made it as a 14 year old in a quickplay (well, Essex U-18 chs, to be precise) with less than a minute, starting from a position where my opponent's king was in the centre - and despite the arbiter wrongly disallowing my claim of the game when my opponent walked into a check!

Admittedly, said opponent also voluntarily walked his king into the right corner (for me). He was smiling inanely at my attempts to win, and playing any old move, until too late ...

[Kevin Thurlow]

"I had to do it in about half a minute earlier this year with about a dozen people watching and managed it with a few seconds to spare. One of my proudest chess moments! "

Same, except I had two minutes I think. When our Board 1 GM announced he was impressed, I was even more proud!

[John Saunders]

It is one of those tricks which is actually quite easy to do once you know how. I included a couple of pages on it in the beginner's book I wrote a few years ago. Not so much because it occurs often (I've never had it in 40+ years of competitive chess and I don't even recall having to bash it out in a blitz game) - more because it makes for a neat little party piece which even a near beginner could probably master with a bit of practice. Someone wrote it up in an article in CHESS a few years ago and made a nice job of explaining it. Basically, you divide the task into two halves - the first bit, driving the king to the wrong corner, doesn't need any special learning, just sensible moves to drive the king to the edge of the board. The second phase, driving the king from wrong to right corner, is non-intuitive and best learnt by heart, taking care to top up your memory by practising it every now and then.

To be perfectly honest, I'm not sure I could have done it until quite late in my chess career, simply because I was too lazy to sit down and force myself to learn it. But, when I finally got round to it, the learning process only took about half an hour. I reckon I could do it given a minute or two, but Jonathan's ability to do it in less than a minute when he was 14 is undeniably impressive.

I believe I posted once before on this subject on the forum and related how I had found a game played by one Russian GM who apparently didn't know how to mate with B+N - Karpov's former second Vladimir Epishin. He had it in the Bundesliga and made a total mess of it, only drawing. Must have been very embarrassing for him. Other than him, every GM game I found on the database was duly won. You'll find plenty of draws but only because databases contain many games played by quite weak players.

[Peter Lalic]

Certainly not the best chess lecture on this subject, but I nonetheless give it a shot at teaching about the N+B checkmate, in this video:
http://www.youtube.com/watch?v=3U0vm8TMqaA

[Geoff Chandler]

Never had to do it.

There is a now famous example fo a Russian GM failing to find the mate.

Robert Kempinski - Vladimir Epishin, Germany 2007.

http://www.chessgames.com/perl/chessgame?gid=1533865

Click on move 127. It's from here the last White piece has just been taken.

The game is drawn after Black's 50 moves have elapsed.

Very painful to watch. He chases the King to the wrong
corner and simply refuses to believe he is wrong.

Any player can make a blunder but this is a shocking
example of a Russian GM in action.

[Alex Holowczak]

The game is drawn after Black's 50 moves have elapsed.

Actually, it isn't!

The game was drawn after black's 179th move, black's 126th move was the last capture, 53 moves earlier.

The game was drawn by stalemate, even after the 50 moves had elapsed!

[John Hickman]

I have read about the W maneuver many times, but had put commiting this mate to memory to the "life's too short pile". Possibly not a bad plan, until about 30 years into my chess career, I get close to K+B+N vs K vs Sandre Waage Tofte in Gibraltar 2008. Actually it was K+B+N vs K+4P.

I needed both my Knight and Bishop to stop the a pawn, and so it was down to whether my King could stop the Black King shephering the f, g and h pawns long enough to snaffle the a pawn and get a minor piece over. Howevever, lurking in the back of my mind was that even if I did this, I didn't know if I could do the mate. I was a bit releived when I forced a perpetual check. When I looked up, a small crowd had gathered, obviously hoping to see perfect mating technique in action, and were quick to point out a rather obvious win for me to round up all the pawns. So not learning this cost me 0.5 points in 30 years.

After a discussion on this group about a different technique involving triangles, I decided to give that a go. I tried it vs an ICC bot, but couldn't get it down. However during one of my fumblings, I thought I recognised a position I could do the W maneuver from. So I gave it a go and nearly got it, fluffing near the end. I then watched the chapter on Karsten Mullers Endgame DVD and gave the W maneuver another go against the bot. After a bit of practice I could do it. After about an hour vs the bot, I reckoned I could now do K+B+N vs K very easily.

Actually, once learnt, it's pretty easy, so hopefully I'll get it in the next 30 years and know how to do it

[Alex Holowczak]

I had this endgame this morning! I won.

[Geoff Chandler]

Hi Alex.

I stand corrected.

Deliberate (lazy) error just to see if anyone was paying attention.

[Paul McKeown]

I've had it twice now. Once I won quickly (4NCL) and the second time my opponent just tipped over his king (Thames Valley) and, to my amusement, claimed I would just study the process in the adjournment!? Marked this down as "Yes, I succeeded", but it would be better if this poll accepted multiple answers!