Most mate options after 6 moves

Found this construction problem from '83 and liked it. I don't know the best solution (yet), and maybe you can top it anyway.

Consider the (help) "game" 1.e4 a6 2.Bc4 a5 3.Qh5 a4. Now White can mate in two ways (and I doubt this value can be increased having 6 preceding half-moves). Maximize the number of possible White mates after 12 half-moves (which you choose).

• The count for 6 preceding half-moves can be increased! 1.e4 f5 2.Bc4 fxe4 3.Qf3 g5, followed by 4.Qh5#, 4.Qf7# or 4.Bf7# Jan 23 at 0:33
• THX. If I had had formulated as a question, the post might have been closed due to one question too many :-))) Jan 23 at 7:29
• I can confirm by brute force that 1. e4 f5 2. Bc4 fxe4 3. Qf3 g5 is the only position with 3 different mates after 6 half-moves. There are also 5 other transpositions of those moves that yield the same position. Jan 23 at 18:04

15:

``````[FEN ""]
1. e3 f6 2. a4 Kf7 3. a5 Kg6 4. Ra4 Kf5 5. Bc4 Ke4 6. Qh5 Qe8
``````

There are 11. discovered check mates plus 7. Qd5# 7. d3# 7. f3# and 7. Nc3#

• I moved the "accepted" to this. Funny, a position like that was I instinctively strived for initially. Jan 28 at 16:15
• I wonder whether there is a way to improve this considering that black has a semi-move spare. Jan 28 at 17:25

11 without discovered checks:

``````[FEN ""]
[startply "12"]

1. e3 e6 2. d4 Ke7 3. Bc4 Kf6 4. Nh3 Kf5 5. Bxe6+ Ke4 6. Qh5 Qe8
``````
• I count 12, 3 knight, 1 pawn, 2 bishop, 6 queen Jan 23 at 22:59
• @CharlesRoddie only 1 bishop mate because alas Bf5+ Kd5 Jan 23 at 23:40

5.5 moves to 14 fool's mates:

``````[FEN ""]
[startply "11"]

1. b4 e6 2. Bb2 Qh4 3. Bxg7 Ne7 4. Bb2 Rg8 5. g3 Rxg3 6. f4
``````

For 6.0 moves, start with something like 1. a3 and then reverse the colors (1. a3 b5 2. e3 Bb7 3. Qh5 Bxg2 etc.).

• This raises the old adage of if unique or not and such is wanted. Jan 22 at 22:23
• @RewanDemontay Usually in such tasks different discoveries do count as different mates; I note that you accepted such an answer yourself <chess.stackexchange.com/questions/24061>. Jan 22 at 22:45
• Very true; I raised the point as Hauke did not specify, and you can never quite know with him. Jan 22 at 23:45
• Hauke says that in this setting, discovered checks are perfectly OK and he already tried in vain to set up such a battery (to his defense, 6 o'clock in the morning half asleep in his head :-) Jan 23 at 7:27
• Accepted; I lack the imagination how a full rook cross shall be beaten. Jan 25 at 22:04

I bid 7.

``````[FEN ""]
[startply "12"]

1. e4 f6 2. Qf3 Kf7 3. Be2 Kg6 4. e5 Kg5 5. d4+ Kh4 6. d5 e6
``````