Masand: When a piece X gives a direct check with its move, all pieces of the same color controlled by X and all pieces of opposite color attacked by X, except for the Kings, change color.
Five promoted Queens are captured on their promotion squares without ever moving (Schnoebelen theme). In orthodox proof games, it is impossible to achieve a Queen Schnoebelen, because there is no way to differentiate the promoted Queen from a Bishop or Rook. With Masand, it is a completely different story: A check by the promoted Queen changes the color of the pieces around her, both orthogonally and diagonally, unlike Rooks or Bishops. In addition, pawns standing close to the promotion squares can be achieved by a change of their color after a check.
I had the idea to use the fairy condition Masand with Berolina pawns for Paul Raican’s Murfatlar tourney in Ohrid, earlier this year. Due to lack of free time, I was not able to achieve a worthy example before the deadline and decided to postpone composing for later. After reaching four Queen Schnoebelens with Berolina pawns, I attempted the same with orthodox pawns. It turned out it was possible to improve that task. (Author)
Looks like multicolored fireworks. What about two more Q promotions?
12.Be2 dxe2 13.Sc3 exd1=Q [a1,c2=b][d6,h5=w]+ 14.Sxd1 cxd1=Q [a1=w][d6,h5=b]+ 15.Rxd1. The sequence [5.gxf8=Q [h6,f7,g8=w]++ … 13.Sc3] was checked by Jacobi v0.5.3 in about 50 min.
This last version quickly demolished when I verified the last 5 moves: 10.Kxg1 dxc2 11.Sd2 Bg4 12.Sb1 cxb1=S 13.Rxb1 Bxd1 14.fxg8=Q [a2=b]+ Kxg8 15.Rxd1
But if the very last promotion is a Rook, then we have a unique sequence:
10.Kxg1 Bg4 11.fxg8=Q [g4=w][a2=b]+ Kxg8 12.Be2 dxe2 13.Sc3 exd1=Q [h5,d6=w][a1,c2=b]+ 14.Sxd1 cxd1=R [a1=w][d6=b]+ 15.Rxd1.
Kostas Prentos
October 23, 2018 13:52
Although it may be possible to achieve more than 5 Queen Schnoebelens in a Masand proof game, having spent several days testing and correcting cooked versions to reach 4 and eventually 5 such cases, I realized that it was not an easy task, at all. Based on all the difficulties I experienced, I didn’t even consider going further.
Is it possible that Paul’s suggestion is sound? Just by looking at the final position, I find it extremely unlikely (the diagram in 14.5 moves can almost be reached in an orthodox massacre PG). Of course, it is practically impossible to test similar positions, even with all the progress made by Jacobi. Common sense is the best guide in this case.
No.1338
Looks like multicolored fireworks. What about two more Q promotions?
12.Be2 dxe2 13.Sc3 exd1=Q [a1,c2=b][d6,h5=w]+ 14.Sxd1 cxd1=Q [a1=w][d6,h5=b]+ 15.Rxd1. The sequence [5.gxf8=Q [h6,f7,g8=w]++ … 13.Sc3] was checked by Jacobi v0.5.3 in about 50 min.
This last version quickly demolished when I verified the last 5 moves: 10.Kxg1 dxc2 11.Sd2 Bg4 12.Sb1 cxb1=S 13.Rxb1 Bxd1 14.fxg8=Q [a2=b]+ Kxg8 15.Rxd1
But if the very last promotion is a Rook, then we have a unique sequence:
10.Kxg1 Bg4 11.fxg8=Q [g4=w][a2=b]+ Kxg8 12.Be2 dxe2 13.Sc3 exd1=Q [h5,d6=w][a1,c2=b]+ 14.Sxd1 cxd1=R [a1=w][d6=b]+ 15.Rxd1.
Although it may be possible to achieve more than 5 Queen Schnoebelens in a Masand proof game, having spent several days testing and correcting cooked versions to reach 4 and eventually 5 such cases, I realized that it was not an easy task, at all. Based on all the difficulties I experienced, I didn’t even consider going further.
Is it possible that Paul’s suggestion is sound? Just by looking at the final position, I find it extremely unlikely (the diagram in 14.5 moves can almost be reached in an orthodox massacre PG). Of course, it is practically impossible to test similar positions, even with all the progress made by Jacobi. Common sense is the best guide in this case.