MESON Chess Problem Database

Problem Display
PID: 57765 (2q1k3/2pNB3/2Q1K3/8/8/8/8/8 w - - 0 1)

Surkov, Valery Albertovich

Scacco!, 1995

2q1k3/2pNB3/2Q1K3/8/8/8/8/8

#2

4 + 3

5454 Near Snap 2022

SOLUTION

  • SOUND
  • Sets
    • 1...Qa6
      • 2.Sb6#
      • 2.Sf6#
    • 1...Qb7
      • 2.Sf6#
    • 1...Qxd7+
      • 2.Qxd7#
    • 1...Qa8
      • 2.Sf6#
      • 2.Qxa8#
    • 1...Qb8
      • 2.Sc5#
      • 2.Se5#
      • 2.Sb6#
      • 2.Sf6#
      • 2.Sxb8#
      • 2.Sf8#
    • 1...Qd8
      • 2.Sf6#
  • Tries
    • 1.Qd5?
      • threat
        • 2.Qh5#
      • 1...Qxd7+
        • 2.Qxd7#
      • 1...Qa6+!
    • 1.Qb7?
      • threat
        • 2.Qxc8#
      • 1...Qxb7
        • 2.Sf6#
      • 1...Qa8
        • 2.Sf6#
        • 2.Qxa8#
      • 1...Qb8
        • 2.Sf6#
        • 2.Qxb8#
      • 1...Qd8
        • 2.Sf6#
      • 1...Qxd7+!
    • 1.Qxc7?
      • threat
        • 2.Qxc8#
      • 1...Qxd7+
        • 2.Qxd7#
      • 1...Qxc7
        • 2.Sf6#
      • 1...Qb7
        • 2.Sf6#
        • 2.Qd8#
      • 1...Qa8
        • 2.Sf6#
      • 1...Qb8
        • 2.Sf6#
        • 2.Qxb8#
      • 1...Qd8
        • 2.Sf6#
        • 2.Qxd8#
      • 1...Qa6+!
  • Keys
    • 1.Qa8!
      • threat
        • 2.Qxc8#
      • 1...Qxa8
        • 2.Sf6#
      • 1...Qb8
        • 2.Sf6#
        • 2.Qxb8#
      • 1...Qd8
        • 2.Sf6#
        • 2.Qxd8#

Anticipated by 227465(1926)

FEATURES

  • Static
    • TYPE = BLOCK_THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 1
    • REMOVED MATES = 3
  • Sets
    • Q(b);N_PINS(C)::QAB(A)+S(C),DCHECK
    • Q(b);CHECK,OGATE,P_SPINQ(b),XS(C)::QAB1(A),XQ(b)
  • Tries
    • Try
      • Q(A);
      • Threat
        • QAB(A)
      • Vars
        • Q(b);CHECK,OGATE,XS(C)::QAB1(A),XQ(b)
      • Refutation
        • Q(b);CHECK,N_PINS(C)
    • Try
      • Q(A);
      • Threat
        • QAR2(A),XQ(b)
      • Vars
        • Q(b);N_PINS(C),XQ(A)::S(C)
        • Q(b);N_PINS(C)::S(C)
      • Refutation
        • Q(b);CHECK,XS(C)
    • Try
      • Q(A);XP(a)
      • Threat
        • QAR2(A),XQ(b)
      • Vars
        • Q(b);CHECK,OGATE,XS(C)::QAB1(A),XQ(b)
        • Q(b);N_PINS(C),XQ(A)::S(C)
        • Q(b);N_PINS(C)::S(C)
      • Refutation
        • Q(b);CHECK,N_PINS(C)
  • Actual
    • Q(A);P_PINQ(b)
    • Threat
      • QAR2(A),XQ(b)
    • Vars
      • Q(b);N_PINS(C),N_SPINQ(b),XQ(A)::S(C)
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