Checkmate with knight and bishop in a specific chosen corner.

This is a question for the 'knight and bishop vs lone king' endgame exerts. Woud it be possible to give checkmate with a knight and bishop against lone king, from any given position, to a chosen corner?

And if it is possible would it be possible withing the 50 moves rule?

I mean to be able to choose one of the 2 corners from the start, so to force the opponent king to that chosen corner to mate him there and only there.

My guess is it is possible but I'm not certain. 

Yes

I can do it 9 times out of 10

Go to the chess terms page and find the mate from a certain position, then learn how to get to that position

Also you don't choose the corner, they do and you go with it

You can't checkmate in the "bad" corner (where the corner square is a different color as your bishop).

It is possible to construct such a mate if black really cooperates, but it can't be done in practice. The only way to win is to force the enemy king to a good corner.

If you have a light squared bishop you must check mate your opponent in a white corner. You can choose h1 or a8, whatever you like best :-)

Yes I know I have to checkmate in one of the two opposite corners, on the color where my bishop is on. I just wonder if you can force a mate in chosen corner (one of these 2 corners). @mantine73 says you can't, that the opponent choose the corner and that you have to follow. Can someone confirm this? Is it really impossible to force mate in a chosen corner? I can imagine it wil take longer but is it impossible?

Well, I would start from this position. And it seems to be easy to regroup the pieces.

Thanks for the example. So it is possible from the starting position of the W Maneuver. I wonder if it would be possible from any given position? I sometime need to use Delatang's Triangle Method instead of the W maneuver.

Would it for example be possible from this position? 

Yes it’s possible. I’m not sure what you mean by the phrase ‘chosen corner’ - usually the defender heads for the ‘wrong’ corner, but there’s still time to force him over to the correct corner and checkmate him.

In other words: it can be done from ANY position whatsoever (as long as the defender can’t immediately win a piece)

Lets say the white king were no e3. Very likely you would checkmate on h1. But he doesn't like h1. He wants to checkmate on a8.

I say yes it is possible,but I have no idea if it is possible within the 50 move rule.

PS IMHO it is more interesting if it can be done if we say the knight were not allowed to enter d4, d5,e4 and e5. I think so, but I'm not sure.

Strictly speaking there are forced mates on the squares adjacent to any corner (see variation at Black's move 2 below), but the forced mate adjacent to a bad corner is really of use only to players who have learned only Delétang triangles by rote. The threat of the mate can be used to extract the king from the bad corner into Delétangs first net. (The bishop needs to be behind the long "right" diagonal.)

The method is not quickest but neither is Delétang's triangles as normally explained. That shouldn't be a problem because there are always at least 17 moves spare within the 50 move rule (though it proves to be a problem for some engines and grandmasters).

Yest that's what I mean with the phrase 'chosen corner'.
I want to do this to make practice knight with bishop mate a bit harder. But I don't want to waist my time if it is not possible within the 50 move rule.

@Ladyhawke79

Interesting question; I think it might be at least a close run thing in many cases. Would you accept mate on a square adjacent to a right corner?

It wouldn't be possible from any given position. See for example the following post.

You'd obviously have to practice it against another human because an engine wouldn't know what it's trying to avoid. (For example in the section against SF8 that I inserted in #14, assuming your chosen corner were h1, a human would play 14...Kh4 instead of 14...Kh2. Doesn't avoid eventual mate on h1, but it adds to the 50 move count.)

He's not asking about how to mate with a bishop and knight; he's asking about how to mate with a bishop and knight in a preassigned corner of the same colour as the bishop (and within 50 moves).

By the way "as long as the defender can’t immediately win a piece" needs to be qualified even if the corner is not preassigned. You have positions like this.

or this

or this

and similar, not to mention double attacks and things like this

All told 10.3% of positions in the endgame are drawn according to Syzygy.

Try it blindfolded :-)

@Ladyhawke79

To better illustrate what I meant about practicing against a human rather than an engine, I've played your position against SF14 aiming for mate on a8.

You'll notice that it's hardly different from a normal game. The engine makes no attempt to stay near h1 because it doesn't want to be near h1. It still thinks my objective is to mate anywhere - it can't change its spots.

But you could be struggling to do it within the 50 move rule against a human opponent.

Is it possible to practice here at chess.com this mate against humans?

Thanks.