# No.528 (ND)

 No.528 Nicolas Dupont(France) Original Problems, Julia’s Fairies – 2014 (I): January – April   →Previous ; →Next ; →List 2014(I) Please send your original fairy problems to: julia@juliasfairies.com

No.528 by Nicolas Dupont  – A big surprise! The first PG problem with Disparate condition! As all published PG problems it will participate in the Tournament for Retro and PG problems published at Julia’s Fairies in 2013 – 2014.  (JV)

Definition:

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”. (For example: white Qc1, black Ka8,Qa7 – mate in 1 move. After 1.Qc8#, Black is mated because 1…Qb8? is illegal. The mate is possible also with the neutral nQc1 – after 1.nQc8#. Black cannot move the same neutral Queen.) Every Pawn’s promotion is a Pawn’s move, therefore after such promotion (into any possible piece) the other side cannot answer immediately with its Pawn. We can say that after the move of the figure of type “x” any enemy figure of type “x” falls under Half-moving paralysis. This paralysis disappears immediately on the next half-move, if the opponent plays with another piece of type “y”. (This way it is implemented in Popeye. Another implementation of Disparate you can find in WinChloe, but it is based on the different rules. )

 No.528 Nicolas Dupont France original – 16.04.2014   PG 16                                (14+14)   C- Disparate     Solution: (click to show/hide)     The proof game theme “a promoted Queen is captured without having moved” is well-known and has been reach under numerous fairy conditions (it is obviously impossible in the orthodox setting). To reach it in Disparate, I followed the first plan which came into my mind are which is probably the simplest: A (white) promotion occurs in c8 before Qd8 or Ke8 moved. Then Qd7 is played, immediately followed by Ke7. We are then sure that the promotion is neither a Rook nor a Knight.  Then Ke6 is played, followed by a second move by Qd7. We are now sure that the promotion is not a Bishop, and hence it must be a Queen!  Finally, once its type is fixed, the promoted Queen is captured. Constructing a related sound sequence is not easy, as the above plan shows that several black moves must be played in a strict order. The solution goes as follows:1.d4 Sf6 2.d5 Sh5 3.Qd4 a5 4.Sf3 Ra6 5.d6 Rb6 6.dxc7 Sa6 7.Bd2 d5 8.Sh4 Bg4 9.c8=Q Bxe2 10.Kxe2 e5 11.Kf3 Qd7 12.Bb5+ Ke7 13.Ba4 Ke6 14.Re1 Be7 15.Re2 Qb5 16.Be1+ Rxc8Note that the Disparate condition is heavy used to ensure uniqueness of the move order. This is C+ from the beginning to move 15.5 and from move 4.5 to the end. (Author)

### 3 Responses to No.528 (ND)

1. Geoff Foster says:

An amazing idea and very cleverly composed. It is hard to reach the final position, even if you know what all the moves are! The wPd2 captures on c7 and promotes to Q on c8, and the bBc8 captures on e2. This accounts for all the moves, but if you try to get there it will make you laugh! It is tricky to move a pawn, because the other side can’t move a pawn on its previous or next move. This is why White moves a pawn on move 1, because it is the only time there is no previous move!

2. Paul Raican says:

I admired at this game the idea and also the technique realization. High class.

3. Another partial approach to validating this wonderful composition is to run it as an orthodox proof game. Natch 2.5, though old, delivered 50014 solutions in less than 2 minutes. I took these into a spreadsheet, to see whether any avoided illegal moves. None did! So any cook must involve a “non-pin”, normally illegal, where a line unit moves out of the line between its king and an enemy line unit of the same type. The actual solution exhibits this effect twice.