py_20210525

{

Tries :
} 1.d7-d8=B ? {(thematic try ; threatens} 2.Bd1-g4 # {dominating the bN ;
and} 2...Rc4*g4 {does not extinguish white Bishop species since it remains the Bd8
and therefore is illegal since} 3.h3*g4 {extinct black Rook species)
} 1...Rc4*c5 2.Ra1*a4 # { and not} 2.Bd1-g4 + ? Sf5-d6 ! {but black parry with} 1...d3-d2 ! 2.Bd1-g4 + d2-d1=S ! {
} 1.d7-d8=Q ? {(threatens} 2.Qd8-a5 # {and not } 2.Qd8-b6 + Ka7*b6 # ! {)
without Pd5, there would be } 2.Qd8*d3 # {extinguishing either of the black Rook or Knight species
. without the Pe6, } 2.Qd8-d7 {would mate, dominating the bN
} 1...Rc4*c5 2.Ra1*a4 # {or} 2.Bd1-g4 # {but} 1...Ka7-a6 ! {simply counter the threat

} 1.d7-d8=R ! {(threatens} 2.Ra1*a4 # {by double check.} 2...Rc4*a4 {does not extinguish the white Rook species since it remains the Rd8
and therefore is illegal since} 3.Bd1*a4 {extinct black Rook species.)
} 1...a4-a3 2.Ra1*a3 # {
} 1...Rc4*c5 2.Bd1-g4 # {

The threat in the try becomes variation mate (on 1...Rxc5) in the real game and vice versa

Two-coloured AUW between the tries and the solution}