MESON Chess Problem Database

Problem Display
PID: 192804 (qR2Bn2/1b6/2QBN2r/b1n4r/pkp3R1/7p/1PP5/7K w - - 0 1)

Winn, DL

The Observer, 1939

(First published on Sun Nov 12 1939)

qR2Bn2/1b6/2QBN2r/b1n4r/pkp3R1/7p/1PP5/7K

#2

9 + 11

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Rh4
      • 2.Bxc5#
    • 1...Rd5
      • 2.Qxa4#
      • 2.Qb5#
  • Tries
    • 1.Kh2?
      • threat
        • 2.Qxa4#
        • 2.Qb5#
      • 1...Bb6
        • 2.Qb5#
        • 2.Qxb6#
      • 1...Bc7
        • 2.Qb5#
      • 1...Bd8
        • 2.Qb5#
      • 1...Qa6
        • 2.Qxa4#
      • 1...a3
        • 2.Qa4#
        • 2.Qb5#
      • 1...Sd7!
    • 1.Be5?
      • threat
        • 2.Bc3#
      • 1...Se4
        • 2.Qxa4#
        • 2.Qb5#
      • 1...Rxe5!
    • 1.Re4?
      • threat
        • 2.Qxa4#
        • 2.Qb5#
      • 1...Bb6
        • 2.Qb5#
        • 2.Qxb6#
      • 1...Bc7
        • 2.Qb5#
      • 1...Bd8
        • 2.Qb5#
      • 1...Qa6
        • 2.Qxa4#
      • 1...a3
        • 2.Qa4#
        • 2.Qb5#
      • 1...Sd7!
    • 1.Rxb7+?
      • 1...Bb6
        • 2.Qb5#
        • 2.Qxb6#
      • 1...Qxb7!
  • Keys
    • 1.Bf4!
      • threat
        • 2.Bd2#
      • 1...c3
        • 2.Bd6#
      • 1...Rd5
        • 2.Qb5#
      • 1...Sb3
        • 2.c3#
      • 1...Se4
        • 2.Qxa4#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 1
  • Sets
    • R(g);N_GUARD::B(F),XS(f)
  • Tries
    • Try
      • K(A);N_SPINQ(E),P-FLIGHT
      • Threat
        • DUALS(2)
      • Vars
        • B(e);P_PINB(F)::QAR1(E)
        • B(e);::QAR1(E)
        • Q(j);::QAR1(E),XP(b)
      • Refutation
        • S(k);
    • Try
      • B(F);N_PINS(f)
      • Threat
        • B(F)
      • Refutation
        • R(g);XB(F)
    • Try
      • R(D);N_SPINQ(E)
      • Threat
        • DUALS(2)
      • Vars
        • B(e);::QAR1(E)
        • Q(j);::QAR1(E),XP(b)
      • Refutation
        • S(k);
    • Try
      • R(H);CHECK,N_SPINQ(E),XB(i)
      • Refutation
        • Q(j);P_PINQ(E),XR(H)
  • Actual
    • B(F);N_PINP(d),N_PINS(f)
    • Threat
      • B(F)
    • Vars
      • P(d);OGATEB::R(D)+B(F)
      • R(g);N_PINQ(E)::QAR1(E)
      • S(f);SBLOCK::P(C)
      • S(f);N_PINQ(E)::QAR1(E),XP(b)
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