Good old times 13

1.b5 b4 2.bxc4 b5 3.cxd3 bxc6 4.dxe2 cxd7 5.e1S dxe8S#

A quartet of lightsquared white bishops against a quintet of black knights together show elusive 100$ theme. To give checkmate in five, Pb2 must promote to knight at e8. Consequently, it is Pb7 who must annihilate Pd3 so that Bc2 guards. After the dust settles, there is unique tempo move for Black in its 5th move, just a knight promotion.

a) 1.Qh3 g8R 2.Rg3 d8R#

b) 1.Ra3 g8Q 2.Qb3 d8Q#

Placement of wR determines good final square for bQ. In a) it is h3 as there bQ is interfered with respect to line d8-d1. In b) it is b3 as there bQ can be paralyzed from g8.

The main idea shown is black Bristol in both directions, combined with matching white promotions. Promoted piece on g8 paralyzes the second black piece of Bristol, while promotion on d8 is chosen so that the first black Bristol piece cannot capture it.

1.d1MA Ge5 2.e1MA+ MAe2 3.MAb2 Ga1#

Although there is only one solution here, there is quite a lot going on in it:
- two fairy promotions with one-way motivation for mao promotions,
- switchback of white grasshopper,
- a checkmate over immobilized mao (this would be thematical in the 7th TT CCM).

Can a similar content be shown in two or more phases?

1.h1LI d8LI 2.LIc6 Sd6#

1.h1G d8G 2.Gd5 Sc5#

Matching promotions to lions and to grasshoppers raise question: why other promotions do not work? While solution with lion promotions is easy (only bLI can move to c6, only wLI can check from d8), grasshoppers have to be motivated more softly (bLI would check wK from d5, wLI would prevent bG from moving to d5).

a) 1.Bxd5(nNd8) nNxe5(nBf8) 2.Rxe5(nNe8) nNxe8(nNe1)#

b) 1.Sxd5(nNd8) Gxc7(nBf8) 2.Rxc7(nGc8) nNxc8(nGc1)#

The first three halfmoves are captures resulting in rebirths on the 8th row of the board (two by Black - neutral fairy pieces are reborn there), while the mating moves are double checks by nBf8 and fairy pieces reborn on the 1st row.

The position is in my preferred form for h# with neutral pieces, i.e. with wK as single white piece. Of course, this problem could be competing in the 17th TT CCM that was dedicated to problems with mates by neutral pieces.