B+N vs King Simple Theory

Yes, one more topic about that. I've seen people asking for help on that and getting tons of advices, many including hard schemes and theories. It isn't so easy to actually mate with bishop and knight, cause there are subtleties. But the theory is small. There are four patterns to remember, and they are almost identical.

Knowing opening, middlegame and endgame theory doesn't ensure a win every match (furtunately!). It is the same here. I may blunder sometimes if playing this, but will win most of the time. If you are looking for a 100% easy win method or something, forget this topic. It will guide you to the (likely) win.

------------------------------------------------------------------------------------

The things you have to know or to do to mate:

1) Know how to push enemy's king across one edge of the board, from one corner to that he will be mated.

2) Know the "pushing patterns".

3) Associate those patterns with the way you lead the opponent's king to the right corner. Which means:

4) Practice on that. Sorry! (smile)

The fourth item is very important. I suppose that if you are spending time with this ending, it is your intention to gain skills maneuvering those pieces and getting a better understanding on some chess mechanics. Simply knowing the patterns and the way to push the king probably won't be enough to ensure a win, although it might raise your chances.

----------------------------------------------------------------------------------

1) PUSHING THE KING ACROSS THE EDGE

I won't discuss much of that here, cause it is by far the easiest part and is widely covered. If you haven't seen the subject before, know that the mate will occur in the corner which color is that of the bishop's square color, though it may be the bishop or the knight to perform the checkmate.

Just pay attention on how the bishop and the knight work together blocking the king, the two possible variations on black's move and the right move in the critical position. And try playing as if you were black - getting wrapped will carve the pattern in your mind much better than if you try to figure out how to move white's pieces.

Now put it on the board, from the starting position, and try playing both black and white the same time. DON'T play against the computer. When you think it is burned into your head, move on.

If it is too hard for you, give up chess.

...

Just joking!

--------------------------------------------------------------------------------

2) PUSHING PATTERNS

Now to the fun part. Here you are:

Quite similar, aren't they?

The idea is: once you reach those positions (and you will be always looking for them), it is "easy" (natural) play. The opponent king WILL be pushed towards the edge/corner.

The "pushing patterns" appear in the starting position and on move 11.Nf2. Moves 5.Bf4 and 7.Be3 might also be included as relevant patterns, where the bishop and king work together. But they are quite obvious and I'll keep things as simple as possible, so try to remember the four patterns mainly. The others will be rememberd forever once you do your training.

As you may have realized, what you do memorize are not only the "pushing patterns", but the "plan" (sequence of moves) associated to them. In the first and second patterns (which are played the same way) these moves are natural; in the fourth one it may be tricky, cause playing 11.Nf2 doesn't seem natural, at least to me... I always felt as if something was hanging, until I trusted the power of the "pushing patterns" and let it go!

The third pattern is important, cause it transposes to the first:

You may try playing it as the first, just to check if it works the same way!

--------------------------------------------------------------------------------------------

3) ASSOCIATING THE "PUSHING PATTERNS" WITH THE "PUSH ACROSS THE EDGE" PATTERN

The magic is:

4) PRACTICE

Once the lone king reaches the edge, he may give you the opportunity to match an in-between move in the "push across the edge" part. You don't have to make him move to the wrong side, then move all across the edge. I remember that, in some positions, it was even harder to do that way!

Using the "pushing patterns" is much more flexible, and the best part, really do something usefull other than just letting you know how to win in B+N vs. lone king.

The following moves are the "complete" guide, whit the important variations. Some sequences are repeated (they may happen in different times during the game).

While watching it, try to find the "pushing patterns" when they occur. It should be natural to visualize them before they are played, so you can actually play them, but that can only be achieved with practice!

Some points:

1) The "pushing patterns" happend in 3.Nf6+, 8.Ke6 and 16.Nc5 in the main line. 6.Bf6 and 14.Bd4 are patterns for King + bishop.

2) Moves 21.Kf4! and 23.Kf4! in the alternative lines are very important. They arise from identical siutations and lead to the same pattern - one you haven't seen yet! Yes, I lied to you...hehehe...there are five patterns, the last being:

Alternate between 2.Nd2, in the main line, and 2.Nf2 in the alternative one, and you will see the associated plan. Very easy.

This pattern isn't a "pushing" one, but a "blunder pattern". You'd memorize it for the sake of 20% more chance of winning (calculated by a martian friend of mine).

Playing Ng3?? instead of Kf4! is tricky, cause it seems natural. The lone king reached the edge, the knight and king look like they match a "push across the edge" pattern... but the bishop is out of place, related to white's king. Just slightly. Thus, the lone king manages to escape. Game over.

You can be somewhat sloppy until the lone king reaches the edge. After that, enter "blunder mode" and remember the fifth pattern.

3) Can you associate the position after 22... Kd1 (main line) with a "pushing pattern"?

4) The position after 20... Kd1 is where white's player should see an opportunity to match a "push across the edge" pattern. Don't try to divine, train until you can play it naturally.

-------------------------------------------------------------------------------------

So, the steps to mate with B+N vs Lone King are:

1) Use your knowledge of the "pushing patterns" (four) and their associated plans (moves) to push the lone king to the edge, or close to it.

2) Once the lone king reaches the edge, turn on Blunder Alert (fifth pattern).

3) Be on the lookout for opportunities to match a "push across the edge" pattern, once the lone king is in the edge or close to it.

And remember, you gotta practice so things go right. If you found a simple guide on "how to play without thinking", congrats - you are ready to leave chess!!!

Nice to know, how many times will it come up?

Just to remark it, the intention of this study is beyond reaching checkmate. It is a learning tool.

I found the above ideas while trying to solve the problem, and came up with them. It is far from a finished theory, and anyone who would like to improve it, even to say it has not worked for you or is as hard as any other explanation in the subject, is more than welcome to do so. It worked for me, though I may have failed to pass the ideas.

If you are going to post to state B+N vs. king is of rare occurance, please don't. It won't improve the discussion.

Although it is uncommon, it is one of the best lessons one can learn. It illustrates harmony, coordination,efficient use of every piece, zugzwang, patience, and geometrical motifs of the chessboard.

thanks, great thread

Perhaps you could elaborate on that just a bit for us patzers who might not understand the terminology you are using (AKA, me)

Once the black King is in the dark sq corner its known 19 move to mate in other corner. Done deal. October 1979 Chess Life GM Bruce Pandolfini gave the Triangle pattern.

Called Delatang's Triangle Method, see here http://en.wikipedia.org/wiki/Bishop_and_knight_checkmate.

I find the B+N ending fascinating. Best way to learn it is to find a method that's based on some simple visual aid, like the Delatang triangles, then just practice it ad-nauseum vs computer, setting up a different start position each time.

Here's a post I submitted that details a two-stage approach to this ending that I learnt from Jesus de la Villa's 100 Endgames You Must Know: http://blog.chess.com/Renegade131/bishop-amp-knight-win. I invented for myself a visual aid for the last part of this method that I exotically call The Pharoah's Tomb! lol. Works for me, but this Delatang Triangles method looks simpler and I might switch. The question is, how easy is it to get the opposing king into the triangle and your pieces into place?

Edit: Actually, screw dat, De La Villa's method works fine for me, get it every time. He gives you a way to dig the enemy king out of the opposite corner (your king on the pivot point), then the mechanical procedure to push the enemy king to the mating corner (The Pharoah's Tomb!).

This article made my day. Thanks a lot 

thanks!

Kudos for wasting time, every basic endgame theory book has what you said, not to mention that there are countless videos on youtube.

I've played it. Also when you see a few more pieces on the board you can point to that endgame to get you the win. Or the other way around to force your opponent into this endgame thinking the same thing you are and still getting a draw.