can you mate with a knight , bishop,and a king?

can you mate with a knight , bishop,and a king?

Not a chance! never had it occur in nearly 37 years of play (although I've had K+B+B V K twice), don't see the point in learning such an oddity.

I've had it occur once here on chess.com

Didn't have the time to mate him though, wanted to join a new tournament, and it was my last game in an ongoing tournament.

Yeah, I can. Doesn't take too long to learn I found, there are a few key patterns needed and that's it really, as long as they stick.

Mate can absolutely be forced with K+B+N vs. K from virtually any position. I wouldn't exactly call it easy, but with practice it can become second nature. I advise that you take the time to learn it and practice it plenty, so that you won't be clueless if that material configuration were to ever arise in one of your games.

I learned it a while ago, and to test myself i played with the endgame against deep fritz 12 (though i had to turn resignation off!). i was able to win so i think ive got it

Here's a tutorial: http://www.answers.com/topic/bishop-and-knight-checkmate

Here's where you can test yourself: http://www.chess-poster.com/chess_problems/mate_king_and_bishop_knight.htm

I should say that if this occurred in a game, I don't know if I'd be able to do it. I know two techniques, but the trick is being able to put them together. It would be interesting to know it cold, where you could do it even with 1 minute left on your clock.

I could not do it. But in over 50 years of chess I've never had it come up in one of my games.

I'm sure there are some willing knights bishops and kings around.

I would really like to teach myself the technique so its like second nature, but there are much better ways that I could spend my time improving my game in that time instead of memorizing a very rare checkmate that comes from a position which my opponent would resign long before it occured.

I actually had a game where I was going to have to do the 2 bishop checkmate pretty recently, which I could blitz out in a minute if I had to, but my opponent resigned before I could do it

I learned the techinque. First you must push the other king to the corner/side of the board (this is easy). Then using memorized patterns (the hard part) push the king to the corner of your bishop's colour. It requires you to spend the time and memorize the moves though (most notabely the knight's "w" manuver).

The only mate I find especially difficult is K+Q vs K+R, though.

no.

subquestion: would it be bad sportsmanship to sacrifice a piece and get to K vs knight , bishop,and a king. 

if you were a little down material and make your opponent prove he could mate with knight and bishop?

It very possible to do so, however I, myself, cannot do this; I think even GMs do not have an easy time performing this feat.

I've had situations where the prospect of the knight and bishop checkmate is hanging over the board. See, most people don't know how to do it in the right time. I might even be better than average with the two pieces I know about it.

I've never reached it though. Those damn pesky pawns - my opponent always manages to keep one or two of them around.

But to the question. If I had knight against knight, bishop, and pawn, I might very well sacrifice the knight for the pawn to reach a lost endgame with practical drawing chances.

I realized that I may have slightly misunderstood the OP. Can we, personally, mate with that configuration? I can, yes, but I like to give myself refreshers and reminders, because it is uncommon. Can it be done at all? Absolutely, without a doubt, mate is forcible from virtually any position in this configuration. Some cunning players may try this as a last-ditch drawing technique (i.e. reducing the material to K+B+N vs. K), banking on the fact that you won't know how to do it. But make no mistake, it can be done.

It's extremely difficult but yes.  Did it once about 30 years ago.  As I recall, you need to drive the King to the corner of the same color as the bishop use the Knight and King to cut off escape and give mate with the Bishop.

Somebody correct me if that's wrong.

In reply to subquestion, I've done it, and it worked! My opponent was 2000+ rated player and he couldn't mate me. It was K+B+N+P vs K+R and i sacrificed the rook for the pawn to stop it promoting. I don't really think it was bad sportsmanship, rather his fault for not knowing it. I don't know it either though, and don't really see the point, as this will cost me at the most half a point in the course of my lifetime.

Which is why it is especially embarrassing if you don't.

It's possible, check out this computer workout exercise:

http://www.chess.com/computer-workout/server/bishop--knight-mate-the-edge