No.310 (ND)

The stipulation, pser-hdia10, means that the diagram position must be reached from the initial game array after 10 white moves, black playing only when in-check but playing also the terminal move (this is the slight difference between pser-h and phser).

Note that the rebirthing rule, in a series genre and under the condition Parrain Circe, is defined as an equipollent move just following the capture, no matter which side is playing.

At least a part of the theme is clear, the “jump” of Bc8 and Ke8 over their line of Pawns. For that some checks are obviously needed, and the lack of Pc2 informs us that the beginning of the solution is probably 1.c4 2.c5 3.c6 4.cxd7+

White Pd7 has to be captured, but by the Bishop or by the King? A piece of inspection shows that Pd7 must rebirth, as the white Queen alone can’t help Bc8 to go outside its cage. If we play Kxd7 there is no white move allowing a rebirth! So the solution must continue with 4…Bxd7 (bPe6) 5.Qe2 (wPc8)

We now have to correctly choose the promotion’s nature. This is certainly a Bishop or a Queen as white must rapidly provide several checking moves. Let’s call it BQ for the moment. We then have 6.BQxd7+ Kxd7 (Bc6)

Now Pe6 has to be captured to be able to go back home, so the rebirth of the promoted piece should occur on c8, and hence the solution continue with 7.Qb3 (BQc8+) Kd6

We are close to the end, after 8.BQxe6 white must play 9.Qa4 to allow the pawn rebirth Pd7. The end of the solution is now clear, 10.Qd1 KxBQe6. As the black King can’t be in-check before white’s move 10, it implies that BQ is in fact a Bishop! So the full solution is:

1.c2-c4 2.c4-c5 3.c5-c6 4.c6xd7 + Bc8xd7[+bPe6] 5.Qd1-c2[+wPc8=B] 6.Bc8xd7 + Ke8xd7[+bBc6] 7.Qc2-b3[+wBc8] + Kd7-d6 8.Bc8xe6 9.Qb3-a4[+bPd7] 10.Qa4-d1 Kd6xe6

This is C+ with the forthcoming release Popeye 4.62, version 4.61 seems buggy as it doesn’t detect this solution.

The black part of the theme is figurative (Bc8 and Ke8 over their line of pawns) while the white part of the theme is two-fold: a capture-less circuit from the Qd1 together with a “Donati” captured promoted Bishop (a promoted piece is called “Donati” when it leaves and then goes back to its promotion square). (Author).