[Retros] Series proof games leading to a checkmate in one move.

[Nicolas.Dupont at math.univ-lille1.fr]

Dear retro fans,

The following series (exact) proof game has been discovered some years
ago, by various members of the french website France-Echecs :

1.c3 2.Qa4 7.Ka5 8.b4

It leads to a checkmate in one move by the black side, namely c6#, and is
probably the shortest series proof game permitting such a #1.

You can regard this as a kind of helpmate series problem, beginning with
the initial game array (and with reverse colors, i.e. we prefer white to
begin than black, this is more natural in that setting).

Here the last move is with the c-pawn, and N, the number of white moves,
is 8. Andrew Buchanan and I proposed to extend this result, by asking :

For each of the remaining black 15 pieces, which is the minimum value of N
achievable ?

The massed brains of France-Echecs have achieved the following records
(thanks to Popeye, each of them is C+). Will you be able to beat some of
them ? Note that the above question makes also sense for black's 0-0 and
0-0-0, but we were unbable to find a solution in those tricky cases. Note
also that the black move has not to be unique, neither giving check, i.e.
we only need that a move by the selected black piece leads to a checkmate.

Our purpose is to write an article incorporating the best results, with
the scope that they are really the length records. That is why we need
your help... If you are able to show a game with same number of
moves, but fewer captures, this is considered as an improvement.

Thanks and all the best,

Nicolas.

Pa7 (Nicolas Dupont) 12 moves
1.e3 2.Bb5 3.d3 7.Ka5 8.b4 10.Bxg7 12.Bb6 and then axb6#

Pb7 (Arthur Dupont) 11 moves
1.a4 3.Rh3 4.e3 5.Bb5 6.d3 10.Ka5 11.b4 and then b6#

Pc7 (France-Echecs) 8 moves
1.c3 2.Qa4 7.Ka5 8.b4 and then c6#

Pd7 (Jean-Christian Galli) 13 moves
2.a5 4.Re4 5.d4 9.Ke5 10.Bf4 11.e3 13.Bd5 and then d6#

Pe7 (Jean-Christian Galli) 13 moves
2.h5 4.Rd4 5.e4 9.Kd5 10.Bc4 11.d3 13.Be5 and then e6#

Pf7 (Jacques Dupin) 12 moves
1.h4 4.Rxd7 6.Re4 7.d4 11.Ke5 12.Bf4 and then f6#

Pg7 (Arthur Dupont) 11 moves
1.h4 3.Ra3 4.d3 5.Bg5 6.e3 10.Kh5 11.Qg4 and then g6#

Ph7 (Nicolas Dupont) 12 moves
1.d3 2.Bg5 3.e3 7.Kh5 8.g4 10.Bxb7 12.Bg6 and then hxg6#

Ra8 (Andrew Buchanan) 14 moves
4.axb7 5.Rxa7 7.Rh3 8.d3 10.Nf3 11.Bd2 12.Qa1 14.Kc1 and then Rxa1#

Nb8 (Jacques Dupin) 12 moves
1.h4 4.Rxd7 6.Re4 7.d4 11.Ke5 12.Bf4 and then Nc6#

Bc8 (Jean-Christian Galli) 14 moves
4.dxe7 5.exf8=B 7.Bfg3 8.Bcf4 9.e3 13.Kh3 14.Qxd7+ and then Fxd7#

Qd8 (Andrew Buchanan)  10 moves
4.fxe7 5.exf8=N 6.Nxd7 9.Nh6 10.g4 and then Qh4#

Ke8 (Nicolas Dupont & Jean-Christian Galli) 28 moves
1.a4 4.Rxh7 6.Re3 11.hxg8=N 13.Nxf7 14.Nxh8 16.Nxf8 19.Nfb5 20.d4
27.Kh8 28.Rh7 and then Kf7#

Bf8 (Nicolas Dupont & Andrew Buchanan) 15 moves
1.a4 4.Rxd7 5.d3 6.Bf4 7.e3 9.Bh5 10.f3 13.Kh4 14.Bg3 15.Rxe7+ and then
Bxe7#

Ng8 (Nicolas Dupont) 11 moves
1.h4 4.Rg5 5.g3 6.Bh3 11.Kh5 and then Nf6#

Rh8 (Andrew Buchanan) 12 moves
4.hxg7 5.Rxh7 7.Ra3 8.e3 10.Nc3 11.Be2 12.Kf1 and then Rh1#