And also, it IS possible to mate with two bishops and a king!
It IS possible to mate with two knights and a king!
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That's right; mate can also be forced with a Bishop and Knight. (Mate with two Bishops can be forced, but it cannot be forced---only set up---with two Knights.) A lot of people think that K+2N vs. K should be an automatic draw, because mate can't be forced. However, since mate can be achieved somehow, K+2N vs. K is not insufficient material.
Hm. I just realized that a part of my post is a little confusing. To clarify:
K+2B vs. K = forced mate.
K+B+N vs. K = forced mate.
K+2N vs. K = mate is possible, but not forcible.
Aug 30, 2010
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#5
Lol and that is what this forum is all about. And it IS possible to mate with one of each minor! Here is how you do it:
Aug 30, 2010
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#6
I've found a two-minor/king checkmate with all combinations of pieces, so what else should i do on this forum?
Aug 30, 2010
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#7
I see your point... if the opponent is stupid enough, then it is forcible. But all 3 are definitely possible, as shown above.
which is something familiar to all players except absolute beginners 
Aug 30, 2010
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#9
Just about 30 seconds before this post i am making, I made my highest win ever!
The thing is, you're setting up the checkmates very nicely, but you're not allowing Black the best defense. In other words, you're not proving that they are forced mates. In your two-Knight example, Black could play 1. ... Kh6. In your two-Bishop example, the Black King is not obligated to stay on the h-file; he could try to flee to the center of the board. And in your Bishop/Knight example, Black could play 1. ... Kf8 instead of Kh8. You did very well in observing that checkmate is possible with these combinations of pieces. I think your next step should be to study how you can force the checkmates with the two Bishops and the Bishop/Knight combo. (Remember, it can't be forced with the two Knights.)
Dragec, many players may know that the mates are possible, but not quite so many can actually do them. 
And 7thSense, congratulations on the big win!
Aug 30, 2010
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#12
quixote, I am not trying to FORCE the checkmates, I am just showing that they are possible, and not insufficient material. Based on your location, I think you live right around the block from me! (I'm in missouri also)
My point exactly, if the OP would want someone to learn a knight+ bishop mate, he should have played the best possible defence.
But, I would bet a beer that he doesn't actually know how to mate within 50 moves, so I asked about the reasons behind posting the obvious facts 
Aug 30, 2010
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#14
Exactly. It is extremely unlikely to happen. Gotta jet! Seeya later guys
I see what you're getting at now. Still, knowing how to force these checkmates is very valuable, and it can give you a big advantage. I see that you're a Platinum member; you ought to watch some of the videos available on Chess.com to learn about how to clinch the win in these scenarios. Good luck!
Of course, mate is possible even with a single knight or a single bishop against some material.
However, it seems to me that the technical term "insufficient mating material" is intended to mean something specific and well-defined as regards the USCF rules. I have seen something that seems to be paragraph 8d in these rules, and I have seen a Q+A in the USCF clock rules that have stated that a player being flagged while having R+P vs N will have the game declared a draw.
Does anybody know anything specific about these USCF rules and their common implementation in tournament play / chess server play in the US, and wish to share their knowledge here ?
ilmago, "insufficient mating material" is one thing, perhaps you meant "insufficient losing chances" ?
Anyhow, IMO this may as well deserve its own thread, or to be posted in the threads regarding draw/wins on time, and not in this thread
I do mean "insufficient mating material" and not "insufficient losing chances". (I know a bit about both, and that the latter rule has ceased to be used in many tournaments.)
Believe it or not, there IS a checkmate with 2 knigh
ts and a king. Here it is: