# Eighteen queens

FabianFnas
Posers and Puzzles 22 Nov '08 08:05
1. 22 Nov '08 08:05
In the thread : "2 Queens", in the Forum "Only Chess", AttilaTheHorn wrote: "Theoretically, it's possible for each side to have 9 queens."

Is it? Or not?

Problem: Show a game, from move 1 and onward, where every pawn is promoted, so the result will be 18 queens on the board.
2. 22 Nov '08 08:121 edit
Originally posted by FabianFnas
In the thread : "2 Queens", in the Forum "Only Chess", AttilaTheHorn wrote: "Theoretically, it's possible for each side to have 9 queens."

Is it? Or not?

Problem: Show a game, from move 1 and onward, where every pawn is promoted, so the result will be 18 queens on the board.
And if I did read the thread to its end, I would discover that one solution is already there...

I've sent a message to the moderator to delete the thread.
3. 22 Nov '08 09:18
Ive recorded it once. On move 99 queen #18 comes on the board. It would be interesting to see what is the lowest possible moves. Or is there a solution for that too already?

4. 22 Nov '08 09:36
This is not possible in 40 moves (which would be the minimum required by length of time it takes a pawn to promote alone)

Here's my first attempt. It's 60 moves, which means a whole 20 moves of "waste" It's the shortest posted on this forum so far though, and gives people something to beat ðŸ™‚

5. 22 Nov '08 13:10
Originally posted by doodinthemood
This is not possible in 40 moves (which would be the minimum required by length of time it takes a pawn to promote alone)

Here's my first attempt. It's 60 moves, which means a whole 20 moves of "waste" It's the shortest posted on this forum so far though, and gives people something to beat ðŸ™‚

[pgn]1.a4 b5 2.a5 b4 3.a6 Bb7 4.axb7 b3 5.Ra2 bxa2 6.b ...[text shortened]... 54.Qa2 d1=Q 55.Q8a3 Kg4 56.Qd8a5 f4 57.Qac3 f3 58.Qhf7 f2 59.Qfa7 Qfe2 60.Qa7a5 f1=Q [/pgn]
Hmm this one is cool, but its not 18 queens. So I guess we have 2 problems. Least possible moves for 16 queen promotions and the other having 18 queens on the board ðŸ˜‰
6. 22 Nov '08 18:16
WHOOPS!
you're right. Silly me. Stick with the old problem, I just was mentally counting the starter queens as inferior, so ended up capturing them.
7. 22 Nov '08 22:111 edit
Originally posted by doodinthemood
This is not possible in 40 moves (which would be the minimum required by length of time it takes a pawn to promote alone)
I think we can prove that the lower bound must be higher than 40.
Each pawn needs to make 5 moves to reach the other side of the board, so that is 16x5 half-moves. Also, the a-file pawns will bump into each other, so at l ...[text shortened]... (I think - I am a bit shaky on this one).
Now I just need to find _which_ 45 moves will do it!

Nice problem!
8. 22 Nov '08 23:19
Done an eighteen one which will probably be cooked quite easily.

9. SwissGambit
Caninus Interruptus
23 Nov '08 04:441 edit
Here's one in 51.5 moves:

10. 23 Nov '08 10:40
very nice. i think will be difficult to top that. maybe a task for those proof game experts? (which i am not)
also funny that a knight survives on each side ðŸ˜‰
11. SwissGambit
Caninus Interruptus
23 Nov '08 19:46
Originally posted by crazyblue
very nice. i think will be difficult to top that. maybe a task for those proof game experts? (which i am not)
also funny that a knight survives on each side ðŸ˜‰
Those surviving Knights cost me a move each, unfortunately. They're in the way of the promoting pawns and there's no way to take them with the promoting pawns.

I'm now working on a scheme where the promoting pawns have no obstacles on the back ranks.
12. SwissGambit
Caninus Interruptus
24 Nov '08 01:39
Originally posted by SwissGambit
Those surviving Knights cost me a move each, unfortunately. They're in the way of the promoting pawns and there's no way to take them with the promoting pawns.

I'm now working on a scheme where the promoting pawns have no obstacles on the back ranks.
Here's a much better scheme with even some bonus captures available on the back ranks to save even more time:

49.0 moves now.
13. SwissGambit
Caninus Interruptus
24 Nov '08 02:31
Originally posted by SwissGambit
Here's a much better scheme with even some bonus captures available on the back ranks to save even more time:

[pgn]
1. f4 h5 2. f5 h4 3. g4 h3 4. g5 a5 5. c4 a4 6. b4 a3 7. b5 d5 8. c5 d4
9. Bb2 e5 10. Bg2 e4 11. Nc3 dxc3 12. Nf3 exf3 13. e4 axb2 14. a4 hxg2 15. h4
Rh6 16. gxh6 Ra6 17. bxa6 Bd6 18. cxd6 Be6 19. fxe6 f5 20. e7 Kf7 21. e5 c5
22. d4 ...[text shortened]... e7 b2 46. d8=Q bxa1=Q 47. Qdd5 Qfa6 48. Qeh5 f1=Q 49. e8=Q c1=Q+

[/pgn]

49.0 moves now.
See the thread in the first post for an update. This task has been done in 3 different ways in 48.0 moves.