King+Bishop vs King+Knight NOT forced draw

Several people thought a king+bishop vs king+knight should be an automatic draw (myself included); but it's not:

I don't get it...I don't see the mate...what's the point?

It would be a draw if black was not so keen to lose he assisted white.

It is a forced draw, but just like a forced win, you dont necessarily have to force it. 

Yes, white would have to be crazy to play Nh7, but the point is that King+Bishop is enough to technically mate against King+Knight, and that this material distribution is therefore not an automatic draw (unlike King+Bishop vs King).

Come to think of it, King+Knight can also mate against King+Knight in much the same way:

the funny thing is that what happens if you ask the referee for a draw? does he say 'yes' if the side with the knight asks for a draw, but 'no' if the side with the bishop asks?

These formal rules always give me a headache , and i would like to know what the manual says, and if it does.

I think it is a rule of self-mate puzzle. I tried several times to solve this kind of puzzle in a three-mover moves. However, sometimes I did not succeed to solve the puzzle. Thanks for this kind of idea. I appreciate your puzzle. God bless!

mandelshtam> These formal rules always give me a headache , and i would like to know what the manual says, and if it does.

In the United States, both players would likely agree to a draw. If that didn't happen, after 50 moves it would be ruled a draw. If one of them flagged, it would be a draw by insufficient material to win on time. If one of them helped the other checkmate them... well, then it's checkmate. I can't help you with the rules in Germany.

In germany i nver met a referee who did something else. however, in chile, weher i lived 5 years, many strange things happened...

 it can happend, if king on corner right?

I guess it's the same - for bishops

(btw this is my first puzzle post! xD I'll probably do it all wrong

Same goes for the cooperation ^^

i would probably lose some how

I should just clarify - this wasn't meant to be a "puzzle"; it was just a demonstration that those pieces do not imply an immediate and automatic draw.

I mistakenly used the word "forced" instead of "automatic" in my original post, so this may have caused some confusion.

If one player does not stupidly allow the other to mate him in this way, then it will *become* an automatic draw only after the 50 move rule takes effect (i.e. 50 moves after the last capture or pawn move). So if you're playing a blitz game in this position, er - make your 50 moves quicker than your opponent, or you will lose on time.

would that really be a draw in the usa if someone flagged?  With Fide rules it would be a loss if you flagged, because with the worst moves you would lose. 

I'm looking at USCF 14E right now, which states you cannot lose on time (even with a delay clock) if your opponent has only:

• King
• King & Bishop (and no forced win)
  
• King & Knight (and no forced win)
  
• King & Two Knights (and no forced win, and you have no pawns)

Presumably because, your opponent would never win these endings on the board. The series of moves required (above) is pretty contrived.

yeah, makes sense.  I think Fide should add that to their rules, which afaik currently assume worst play even in such ridiculous situations. 

I can mate on 2nd move as black. Does that mean I have a forced mate? no.

Just because it is possible does not mean it will ever happen in real life. Although admittedly, 2nd move mate is probably more likely than either of those scenarios you've shown with K+N v K+B etc.

I don't know what you mean by automatic. Nothing in chess is automatic. All those charts you're showing are called helpmates rather than anything that people would play otb.

mueller wrote:

I don't know what you mean by automatic. Nothing in chess is automatic. All those charts you're showing are called helpmates rather than anything that people would play otb.

I don't know how I can explain it any more clearly. Lord knows, I've had enough attempts at it. Maybe nobody really reads an entire message. Who knows?

In chess, a game is automatically over when a king is checkmated.

In chess, a game is automatically drawn when a king is stalemated.

In chess, a game is automatically drawn if the only pieces left are insufficient for checkmate. The four such possible scenarios are:

1. King vs King, or
2. King vs King & Bishop, or
3. King Vs King & Knight, or
4. King & Bishop vs King & Bishop if and only if both bishops are on the same coloured squares.

In chess, believe it or not, a game is automatically drawn if one player has only a King and the other player runs out of time on the clock.

Got that? Good. Next:

A game is not automatically drawn after a position is repeated three times. One player must claim the draw, and the other is not permitted to refuse it. Nevertheless, the draw claim must be made if a draw is wanted.

A game is not automatically drawn if the last 50 moves made by each side result in no piece capture or pawn movement. One player must claim the draw, and the other is again not permitted to refuse it.

Ok. Have you worked out what's coming next? I imagine not, but it was the original point of the post:

A game is not automatically drawn, nor may a draw be claimed, if the only pieces left are:

1. King & Knight vs King & Bishop, or
2. King & Knight vs King & Knight, or
3. King & Bishop vs King & Bishop if and only if the bishops are on differently coloured squares.

Players in this situation can obviously offer and agree upon a draw should they so wish, but are under no obligation to do so.

This is for FIDE; likesforests pointed out that USCF would require you to demonstrate a forced win to an arbiter should you wish to avoid a draw under USCF rules.

Everyone pointing out the obvious fact that an opponent would have to be pretty stupid to cooperate, or - wait for it - these would be helpmates(!) are astonishing in their capacity to utterly miss the point. This is a post about the player's need to understand when they can formally and implicitly invoke the rules of draws, or when they would need to explicitly claim a draw, and when a draw is neither automatic nor claimed, but merely agreed upon. It was not supposed to be a half-witted opportunity to render trivial, non-sensical puzzles in the hope of eliciting comments of corresponding quality. Sigh^2.

just a thought, wouldn't someone have to be a complete idiot if they where to co-operate in the way white did in the first post?