Did you notice White has three rooks? 😀
In a proof game the moves need only be legal - they do not have to make any sense as moves in an actual game.
Anyway, what would you play in this position (you are white and it's your turn):
And a set of little challenges (but don't forget BDP's problem!)
Find positions with minimal number of chessmen where:
1. Knight promotion is the only winning move;
2. Rook promotion is the only winning move;
3. Bishop promotion is the only winning move;
4. Knight promotion is the only drawing move (solution above);
5. Rook promotion is the only drawing move;
6. Bishop promotion is the only drawing move.
The best solutions I know of are as follows:
Challenge no. 1 - 4 pieces;
Challenge no. 2 - 3 pieces;
Challenge no. 3 - 5 pieces;
Challenge no. 4 - 4 pieces;
Challenge no. 5 - 7 pieces;
Challenge no. 6 - 6 pieces.
Can you find the positions?
Originally posted by David113f8=N+
Did you notice White has three rooks? 😀
In a proof game the moves need only be legal - they do not have to make any sense as moves in an actual game.
Anyway, what would you play in this position (you are white and it's your turn):
[fen]4K3/r4P2/4k3/8/8/8/8/8[/fen]
And a set of little challenges (but don't forget BDP's problem!)
Find positions with min ...[text shortened]... ieces;
Challenge no. 5 - 7 pieces;
Challenge no. 6 - 6 pieces.
Can you find the positions?
Originally posted by David113Here's the first three:
And a set of little challenges (but don't forget BDP's problem!)
Can you find the positions?[/b]
1. Knight promotion is the only winning move;
wKf5 Bg6 Pg7; bKh6. 1.g8N+!
2. Rook promotion is the only winning move;
wKa5 Pc7; bKa7. 1.c8R!
3. Bishop promotion is the only winning move;
wKb4 Nd5 Pb7; bKa6 Pa7. 1.b8B!
The queen was left off the list, because that task isn't possible with 3 units, and trivial with 4 units.
Originally posted by David113Seems there are multiple solutions for this one.
And a set of little challenges (but don't forget BDP's problem!)
Find positions with minimal number of chessmen where:
4. Knight promotion is the only drawing move (solution above);
Can you find the positions?
wKh5 Pe7; bKf6 Qg7
Menaced with ...Qg5#, White's only escape is 1.e8N+, winning the Queen and drawing.
Originally posted by David113I can beat this by 2 units.
And a set of little challenges (but don't forget BDP's problem!)
Find positions with minimal number of chessmen where:
5. Rook promotion is the only drawing move;
The best solutions I know of are as follows:
Challenge no. 5 - 7 pieces;
wKc1 Ph7; bKa1 Pa2h2.
Of course, White can win (1.h8Q#, 1.h8B# ) or lose (1.h8N, 1.K~) but only 1.h8R h1Q+ etc. draws.
Originally posted by David113Using my idea from challenge #5, I can do this one with a mere 4 units.
And a set of little challenges (but don't forget BDP's problem!)
Find positions with minimal number of chessmen where:
6. Bishop promotion is the only drawing move.
The best solutions I know of are as follows:
Challenge no. 6 - 6 pieces.
wKc2 Pa7; bKa1 Ph2.
1.a8B is the only drawing move.