Bishop, Knight & King versus King.

@yureesystem: Yes, I do have a great sense of humor. But I wasn't joking this time. K+B+N vs lone king is quite easy. I like the Philidor's W maneuver. I practiced it a couple of years ago.

Thankyou again.

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While it's possible to force this mate, before you go getting interested in it, take a look at these facts:

1. It's a very rare ending. Most GM's never see one.
2. There are only 263 such endgames in my database of 1,172,256 games in which at least one player was at least 2450 ELO. That's only 1 such endgame in nearly 4,500 games.
3. Of the 263 games, 24 (9%) were drawn because the player with the pieces couldn't force mate.
4. Only 31 were forced mates, in which the player with the bare king forced the opponent to complete the mate. In the 232 other games, the one with the bare king graciously resigned first.

Some interesting character stories in this rarified drama:

• Two Super-GM's with ELO over 2700 couldn't force the mate:

  • Ruslan Ponomariov (vs Daryatkin in 2004, in a blitz game)
  • Alexander Moiseenkko (vs Drozdowski in 2013, also in a blitz game)

• The highest-ranked GM to fail in a standard-time-controls game was Kiril Georgiev, vs Julio Granda Zuniga in 2009, in Pamplona. Other 2600-level GM's to fail were Socko and Motylev (standard) and Sethuraman (blitz).

Of those who forced their opponent to complete the mate in the hopes of getting a draw, Alexander Morozevich holds the record with three attempts; he failed twice (his opponents Ivanchuk and Malakhov were up to the task and duly mated him in front of spectators), and gave up once when he saw it was going to happen when playing against Tal Shaked in the Under 20 World Championship, 1997.

Interestingly, Drozdowski has also seen this ending three times, once in the aforementioned draw against Moiseenko, once as the probable winner (his opponent Viktor Erdos resigned first, in the European Championship in 2012), and once as the loser, against Lukasz Licznerski in 2014. Entertainingly, Licznerski was the underdog by 130 ELO, with a rating of only 2344, and could pull this off!

So, learn it if you want; it may just come up once in your life. But you'll see way more games with equally-matched numbers of minor pieces, and like B v N or R+B v R+N.

Yes, it's rare. But it is one of the four basic mates, and it's not especially hard to learn for a 1500 or higher rated player.

Its difficult endgame to master but worth learning it.

didn't notice post #67.....

till now, thx .....likes the video!

The older chess manuals advocated practicing this as a part of basic chess training. When I took up correspondence chess again after a long hiatus I had this ending come up in one of the first games I played. Since the opponent's king was already on the edge of the board, it cut down the number of moves I needed to work the checkmate, but my early practice paid off and I succeeded. My opponent sourly remarked "I didn't think you could do it." Well I did.  Is it worth the half point? Well, when you have a "won" game before you, it is unsporting not to attempt to take it all the way, if you can. BTW, the superficial Silman endgame book doesn't bother with it, but it can happen and it is satisfying to be able to accomplish it. There's one trick when you've got the opposing king on the edge of the board where there is an opportunity for him to escape.  Unless you know it, the king can get back out into the center of the board. Capablanca in "Chess Fundamentals" says, basically, figure it out for yourself. 

 I got it once in a practice game but that was only once in many attempts. It only takes one slip in the worst case 30 move position to give away a half point. Still there is a technique, but I wouldn't steer into this ending in an over the board game and expect to win. If you have a chess computer it wins infallably and Paul Keres explains how to do it well in his book "practical chess endings" but you can't take the book into a tournament or use a chess computer!

Actually, this is quite easy. One of my practice techniques/party tricks is bishop + knight checkmate blindfolded.

Funny thing is when you do it for casual chess players, they think you saw it all the way from the beginning

It actually happens to me quite often though. That is, I've been playing chess for about a year and I've had either two or three B + N checkmates (I can't remember). Were they necessary? No, I am of course referring to having a bunch of material and instead of using the B + N to promote my pawns, I just checkmate my opponent's king in the corner.

However, I have had quite a few live B + N checkmates because in blitz when my opponent doesn't resign I always (given the opportunity) promote my pawns to B + N and suicide all my other material then checkmate with the B + N.

One way to learn something difficult is first to learn something more difficult.

When you work on analyzing the 2N+K vs P+K ending you will dicover you can drive the opposing king to a corner with only 1 knight plus king. Once you got the hang of this trick you will never ever have trouble any more with caging in a king with king plus knight plus the extra bishop!

Can you make it be the right corner, or will you still have to learn the fairly simple method of driving the king along the edge?

I recall that you can't always get a king from the "wrong" to the "right" corner when you are in the wrong tempo. I never studied this issue systematically, only on a case by case basis playing an engine or reeling off its analysis. I guess it is related to the complicated schemes MARattigan produced with "right" and "wrong" king positions for every pawn block.

In the current context it is merely interesting to know how to drive a king from the center to the side and then further on to a corner. It will give you so much control over this material that you will feel almost ashamed having to add a full bishop to get the king to the right corner!

By the way, what you refer to as the "fairly simple method of driving the king along the edge" will be an eyeopener to the ELO-1500-category that has problems winning the N+B ending. If they knew it, they wouldn't let their opponents king off the hook again and again.

I didn't know that N + K could drive a king to the corner, does this me that any 2N vs. K + P ending is winning provided that the pawn is not blockaded? I thought some where draws.

Even so, surely the knight cannot drive the king to any particular corner. If the king starts running to a dark squared corner, there's no way a K + N can stop him except in some very specific positions.

If the king decides to play Kh8 - Kh7 - Kh8 or Kh8 Kg8 Kh8 etc.) then you need a knight AND a light squared bishop to drive him out of that dark corner.

I pulled off this mate in blitz OTB at Cafe Pantin, in either 2016 or 2015. 

On the contrary, the pawn must be blockaded first. That is the assumption in my previous post. N9531l is well aware of that so I didn't need to explain.

The last tricky part is that you have to mate the king after it has been driven into a corner. That requires lifting the blockade and hurrying the second knight towards the relevant corner to mate the king. Meanwhile the pawn runs and may even promote. Who comes first determines which blockaded pawn positions win and which only draw. Besides the main strategy there are all kinds of tricks like mating with just one knight or mating along the side which makes the complete theory of this ending quite complex.

Depends on where the knight is, for instance: wKf7, wNe7, bKh7: 1. Ng6 Kh6 2. Nf8 and the king is forced out of the corner (though out in the open).