Disparate: If one side makes a move with a piece of type “x” (black, white,neutral, half-neutral, etc., King included), the other side cannot answer immediately by moving a piece of the same type “x”.). A pawn promoting is a pawn move.

No.1232Nicolas Dupont France original – 24.06.2017

Symmetric at-home diagram, interchange (Qd1,Ke1), specific mate.

Note that the purpose of the 2 waiting moves 4… Sf6 and 6… Se8 is not only to get a nice diagram, but more importantly to avoid any move from the black Queen. Indeed with square e8 free, 7…Qe8 is parrying the check!

The stipulation is close to the Quartz TT10 but it is necessary to present this problem after the mating move (and not before) as this move is not unique. The problem is C+ (Popeye 4.77) when the piece types are defined, but it remains C? in full. (Author)

No.1232.1Nicolas Dupont France version of No.1232 – 15.09.2017

The diagram position is less harmonious than in the cooked predecessor, but still “at-home”, and the remainder of the content is kept. The novelty is that this problem is correct, according to a non-official solving program by François Labelle! I also thank Paul Raican for valuable discussions. (Author)

Stipulation asks for any legal play of 6.5 moves ending with mate, where any 28 white or black pieces occupy the 28 squares marked on the diagram.

The final image must be legally achievable, so a solver must provide any proper PG in 6.5 moves.
If there’s more than one PG, the problem is cooked (unless multi-solution was intended and indicated by the author).

A solution can be: 1.d4 Nc6 2.e4 Nd4 3.Qd4 Nf6 4.e5 Ne4 5.e6 Nc3 6.Qg7 Nd1 7.ef7#.
However, it is easy to see that the same position can arise after a different order of these movements.

Why cook? The final position in the “cooked” solution is not mat. Any black pawn move is a sufficient defense.
By the way, PG in the author’s solution is correct (I do not mean a diagram with undefined pieces, only PG).

seetharaman Nov 20, 18:17 on No.1252 (GG) { White and black have made the same moves but in different order. Obviously the position... }

dupont Nov 20, 15:15 on No. 1146 (PR) { Of course, as this is a retro problem... An amount of retro problems are 100/100... }

Nikola Predrag Nov 20, 2:25 on No. 1146 (PR) { Yes Julia, that's what I say. C- or C? could mean "not tested" or perhaps... }

Julia Nov 19, 23:26 on No. 1146 (PR) { Nikola, I believe C- might happen after replacing C? with it. I won't publish a... }

François Labelle Nov 19, 17:26 on No. 1146 (PR) { More votes (notation of problems with unknown status, retros section): feenschach: nothing PDB: nothing Phenix:... }

Does the solver have to find the final image only? Or does he have to find the series of movements that lead to it? Is this series of moves unique?

Stipulation asks for any legal play of 6.5 moves ending with mate, where any 28 white or black pieces occupy the 28 squares marked on the diagram.

The final image must be legally achievable, so a solver must provide any proper PG in 6.5 moves.

If there’s more than one PG, the problem is cooked (unless multi-solution was intended and indicated by the author).

A solution can be: 1.d4 Nc6 2.e4 Nd4 3.Qd4 Nf6 4.e5 Ne4 5.e6 Nc3 6.Qg7 Nd1 7.ef7#.

However, it is easy to see that the same position can arise after a different order of these movements.

I’m far from being an expert in that field but this looks as a cook-solution to me. Well found!

Yes this is a valid cook! François Labelle found almost the same one.

Why cook? The final position in the “cooked” solution is not mat. Any black pawn move is a sufficient defense.

By the way, PG in the author’s solution is correct (I do not mean a diagram with undefined pieces, only PG).

Since the last white move was a pawn move, black can’t make a pawn move.

Yes, you’re right. My hands were faster than my head.