Much harder this. The king must be mated in the corner the same colour as the B. Whilst a mating position exists in the wrong corner it cannot be forced. The defending side will therefore head towards the centre and once driven to the side will attempt to go to the wrong corner. Great care needs to be taken as it will only take a few mistakes and the 50 move rule could be exceeded.
Take this position with black to move
1. ... Ke7
Once again the K head to the centre
2. Bd3 .. Kd6;
3. Kd2
The B & N cannot deliver direct pressure so the support of the King is essential both to protect the minor pieces and to cover escape squares
3. ... Kd5;
4. Ke3 .. Ke5;
5. Hf3+ .. Kd5;
6. Kf4 .. Kc5;
7. Ke5 .. Kb4;
8. Kd4 .. Kb3;
Having been driven from the centre the King heads for the wrong corner
9. Ne5 .. Kb2;
10. Nc4+ .. Ka1;
11. Kc3 .. Ka2;
12. Na5 .. Ka1;
13. Nb3+ .. Ka2;
14. Be4 .. Ka3;
15. Bb1 .. Ka4;
16. Nd4 .. Ka3;
17. Nb5+ .. Ka4;
18. Kc4 .. Ka5;
19. Kc5 .. Ka4;
20. Bc2+ .. Ka5;
21. Nd6 .. Ka6;
22. Bd3+ .. Ka5+;
23. Nc4+ .. Ka6;
24. Kc6 .. Ka7;
25. Nd6 .. Kb8;
Opps, trying to escape the other way now
26. Kb6 .. Ka8;
27. Kc7 .. Ka7;
28. Nc8+
Not 28. Nb5+?? when Ka6; 29. Kc6 .. Ka5; 30. Kc5 .. Ka4 and we start all over again
28. ... Ka8;
29. Be4++
This is not intended to be the shortest way just a demonstration of principles. I am sure someone will tell me its inelegant and they can mate in 18 moves but they have a Tablebase and I don't so they are not really very clever. Could they have done it without the Tablebase?
Originally posted by wormwoodHere we need to stop the king escaping by forming a "net". Maybe the easiest way to remember this is: if Black had played Ka3, White would have played Nb5 and then Kc4. With Ka5, do the same in reverse order.... Ka5, Kc4, Kb6, Nb5, Kc6. Now if we remember that we want the king in a corner controlled by the bishop (a8 and not h8), then you should be able to find the one and only bishop move here that stops the king going towards h8.
okay, this is what I don't get: what if black king goes 16...Ka5 instead of 16...Ka3?
So, Bf5, Kb6, Bd7, etc.
Going back again to...
Maybe here it is tricky to realise that the knight should go to b5 and not e6.
For a crazy reminder... in the book, the Seven Deadly Sins of Chess, Rowson compares a knight to a cowboy with a lassoo. But if the black king is the "runaway steed" we can only lassoo it from behind... we get into problems if we try to lassoo something running straight towards us... 🙂 Alternatively, highlight the "dotted circle" (or part of)that a knight controls and view that as part of the "net".
Originally posted by wormwoodRemember the king cannot be mated by force on a1 as it is the wrong colour which is why he always tries to head there.
okay, this is what I don't get: what if black king goes 16...Ka5 instead of 16...Ka3?
But if 16. ... Ka5
Then-
17. Kc4 .. Kb6;
Trying to escape back to the centre
18. Nb5
The best square to stop the escape
18. ... Kb7;
19. Kc5 .. Kc8;
Lets try and get to that wrong corner shall we
20. Kd6 .. Kd8;
21. Nc7 .. Kc8;
22. Be4
Stopping him escaping
22. ... Kb8;
23. Kc6 .. Kc8;
24. Ne6 .. K b8;
25. Kb6 .. Kc8;
26. Bc6 .. Kb8;
27. Bd7 .. ka8;
28. Nc5 .. Kb8;
29. Na6+ .. Ka8;
30. Bc6++
Once again I do not claim this is the quickest and most effective way but rather an indication of how it is done.
(So all you novices out there. When playing a good player here have the decency to resign this sort of ending. Maybe OTB we will slip up but not on a correspondence chess site where if we are unclear on how to do it we can always look it up. As in so many aspects of life the trick is not to know how but to know something can be done and where to find the answer)
I tried it against an engine:
FEN "8/1N6/8/8/3K4/8/5k2/2B5 w - - 0 1"
1. Nd6 Kf3 2. Bh6 Kf2 3. Ke4 Kg2 4. Ne8 Kg3 5. Nf6 Kg2 6. Ke3 Kg3 7. Bg5
Kh3
8. Kf3 Kh2 9. Kf2 Kh1 10. Nd5 Kh2 11. Nf4 Kh1 12. Ne2 Kh2 13. Ng3 Kh3
14.
Kf3 Kh2 15. Be3 Kh3 16. Bg1 Kh4 17. Ne4 Kh5 18. Kf4 Kg6 19. Ng5 Kg7 20.
Bc5
Kf6 21. Bd6 Kg6 22. Be7 Kh5 23. Nf7 Kg6 24. Ne5+ Kh5 25. Kg3 Kh6 26. Kg4
Kg7
27. Kg5 Kh7 28. Bf8 Kg8 29. Bh6 Kh7 30. Kh5 Kh8 31. Kg6 Kg8 32. Ng4 Kh8
33.
Bg7+ Kg8 34. Nf6# 1-0
Took me 2 minutes.Not the shortest way,I'm sure,but good enough to face it OTB with plenty of confidence 🙂