py_20181127

{

} 1.g7-g8=G ! {

} 1...f2*g1=Q + 2.Sd1-f2 ! {covers check and releases the first row while intercepting the second} 2...Qg1-a1 # {
(} 2.Sd1-e3 ? {would not work : } 2...Qg1-a1 + 3.Rh2-b2 {)
} 1...f2*g1=S 2.Sh4-g2 {limits Rg1 march and intercepts Rh2 and "deprotects" pf3} 2...Sg1*f3 # 2...Sg1-e2 # {
} 1...f2*g1=R 2.Gd5-g2 {intercepts Rh2, limits the march of Rg1 and prevents Nd5-d3} 2...Rg1*d1 # {
} 1...f2*g1=B + 2.Sd1-e3 {covers check while lengthening the march of Bg1} 2...Bg1*e3 # {
(} 2.Sd1-f2 {would allow} 2...Bg1*h2 {)
} 1...f2*g1=BG 2.Gg8-e6 {intercepting Ra6 and blocking the Pe5} 2...BGg1-g7 # {

Task of the 5 promotions}

{

} 1.c3-c4 ! {Blocus which immobilizes Bb4 and allows Queen to play.

} 1...Qb5*c5 + 2.Kd5-e5 # {by masking Rf5, one avoids activating bQ
} 1...Qb5*c4 + 2.Kd5-e6 # {similarly by masking the Qg8
(Note that : } 2.Kd5*c4 + {which "observes" the Bb4 and allows} Bb4*c5 {)
} 1...Qb5-c6 + 2.Kd5-e4 # {similarly by masking Bh1
} 1...Qb5-d7 + 2.Sc5-e6 #{display-departure-file} {d7 no longer needs to be controlled and e6 is observed by the bQ
} 1...Qb5-a6 {or} 1...Qb5-a5 2.Qg8*e8 # {
} 1...Qb5*b6 2.Sg7-e6 #{display-departure-file} {e6 is again observed by the bQ and the Knight captures control of c7
}