Julia's Fairies

No.1309
Paul Rãican (Romania)

Original Retro & PG problems
JF – R2017-18

Definitions: (click to show/hide)

The -17 & =1 stipulation means: retract 17 moves and than stalemate in 1 move.

Defensive Retractor: In Defensive Retractors, White and Black retract (take back) a given number of moves (-n moves), in order to reach a position in which a forward stipulation (e.g. #1, s#1) is met. Given a choice, Black will retract those moves that avoid or delay White’s goal. Unless otherwise stated, Black may defend by mating White through a forward move, if such an opportunity exists after one of Black’s retractions.
The different kinds of Defensive Retractors only differ in the way uncaptures are handled, of course only legal uncaptures are allowed. In Proca Retractors the retracting side decides, if and what man was uncaptured.

Circe Assassin: Like Circe, but when the rebirth square is occupied, the occupant is «assassinated» (replaced) by the captured unit.

Circe: Captured units (not Ks) reappear on their game-array squares, of the same colour in the case of pieces, on the file of capture in the case of pawns, and on the promotion square of the file of capture in the case of fairy pieces. If the rebirth square is occupied the capture is normal.

No.1309 Paul Rãican
Romania
original – 08.07.2018

Solution: (click to show/hide)

white Kf1 Bf3 Sg8 Sf6 pg6 black Kd4 Ra8 pg3

-17 & =1 Proca Retractor (5+3)
Circe Assassin

no animation for Defensive Retractors (JV)

1.Ph7xRg8=S(Ra8, -wBa8)! Rg7-g8+ 2.Bb7-a8 Rg8-g7+ 3.Bc8-b7 Rg7-g8+ 4.Bd7-c8 Rg8-g7+ 5.Be8-d7 Rg7-g8+ 6.Bf7-e8 Rg8-g7+ 7.Bc4-f7 Ke5-d4+ 8.Bd5-c4 Kf5-e5+ (1^st time this position) 9.Kg1-f1 Kf4-f5+ 10.Kf1-g1 Kf5-f4+ (2^nd time) 11.Kg1-f1 Kf4-f5+ 12.Kf1-g1 Kg5-f4+! (avoids the draw by repetition) 13.Bg4-f3 Kh6-g5+ 14.Bh5-g4 Kg7-h6+ 15.Bf7-d5 Kh8-g7+ 16.Be8-f7 Rg7-g8+ 17.Se4-f6 & 1.Sxg3(Pg7, -bRg7) =

First Assassin Proca Retractor ever composed with stalemate in the forward play! The only way to annihilate the bR is either by pinning it or by passive annihilation under bP. As the annihilation must occur in the forward play, white must first lure bK in the corner. This objective can be achieved through a sequence of consecutive preparatory maneuvers:

The unpromotion of wS. This has a triple purpose: lures bR in a position where it can solely oscillate between g7 and g8, creates by suicide the second light square wB and takes the control of g8 for the final stalemate.
Getting wBa8 near the bK. The staircase-like movement Ba8-b7-c8-d7-e8-f7 is needed in order to be able to finally place wB to c4, forcing bK to make one step forward the most distant corner (h8).
Draw pendulum. After the wB gets on d5, both Ks oscillate: wK between f1 and g1, bK between f4 and f5. Finally the bK is forced to release again his central position and forced to play on g5.
King harassment by Bishops. wBf3 forces the bK to get from g5 to g7, wBd5 forces the bK in the corner and the bR on g7.

Now the final blow is possible with two simple Knight jumps, capturing in the forward play the bPg3 and putting it back on g7! (Author)