11071 Players currently online!
Man vs. Machine - good luck!
Turn-based games at any time!
Vote for the best move to win!
Do you have what it takes?
Sharpen your tactical vision!
Get advice and game insights!
Learn from top players & pros!
View millions of master games!
Your virtual chess coach!
Perfect your opening moves!
Test your skills vs. computer!
Find the right private coach!
Can you solve it each day?
Bring it all together!
Beginners, start here!
Make friends & play team games!
News from the world of chess!
Search all Chess.com members!
Find local clubs & events!
Who's the best of your friends?
Read what members are saying!
Is it possible, in terms of a helpmate, for two knights to checkmate a lone king? I'd like to know what people will say.
It's possible if Black errs at the very end, but otherwise White must stalemate before he can mate. Mate can only be forced if Black has a pawn, and even then only if it is blockaded by a White Knight and only within certain ranges of squares. The basic idea is White's King and one Knight restrict the Black King to near a corner, then the other Knight rushes in. White can then give the "stalemate" because Black's pawn can move - but he must do it before the pawn promotes, or to deliver mate on the very next move, even then.
The great endgame composer A.A. Troitzky wrote a treatise on K+2N v K+P a century ago, and it is one of the few endgame analyses which the computer "Table bases" could not improve upon.
Sure, help-mate is possible. It doesn't even have to be in a corner:
They do need assistance of their own King for this, though.
Wow, I didn't know this.
this happened to me and the result was funny http://www.chess.com/livechess/game?id=765978737
It would be interesting to compose a study where three knights have to try and force mate (can it be done?) and can't be helped by the king... something like this with white to move and subpromote with check -this isn't it by the way , so don't try and solve
Ziggy - it can't be done without a helpmate!
The centre of the board won't work; the knights obviously have to be near the K, so two of them are busy protecting each other, but this always leaves at least 4 flight squares for the K.
The edge of the board also doesn't work for the simple reason that the king's square and the 5 squares around it are 3 light and 3 dark squares. 2 knights can take care of 2 light and 2 dark squares, but the 3rd knight can't cover the remaining 1 light and 1 dark square simultaneously, so the K will always have 1 flight square.
So it has to be the corner, say h8. h7 and g8 must be covered by one knight, a second must cover g7, and the 3rd can deliver mate. The question is, how to force the king to h8?
This is the position we want:
"Helpmate" is a term I've never heard before. Can someone provide it's definition?
Helpmate-the opponent helps you to checkmate them
That is some tactic Ziggy!
4/16/2014 - Mate in 3
by Tomulous 3 minutes ago
Can I Become GM in 29 Days?
by winerkleiner 6 minutes ago
The Blind Dude on the Second Floor
by blueemu 7 minutes ago
What do you feel about players that do perpetual checks when they are losing?
by Chessattackman 8 minutes ago
by minor7b5 9 minutes ago
User feedback on new forum topic rules
by kleelof 11 minutes ago
by bouncing_check 11 minutes ago
4/17/2014 - Mate in 4
by stuartking2013 12 minutes ago
by Segway_Enthusiast 13 minutes ago
He really removed all my options...
by blueemu 14 minutes ago
Why Join | Chess Topics |
Help & Support |
© 2014 Chess.com
• Chess - English
We are working hard to make Chess.com available in over 70 languages. Check back over the year as we develop the technology to add more, and we will try our best to notify you when your language is ready for translating!