MESON Chess Problem Database

Problem Display
PID: 251261 (4Q1B1/N1brN3/pP1pqp2/6P1/1Bk3PR/2P2K2/2P5/7n w - - 0 1)

Shannon, J

British Chess Magazine, 1933

4Q1B1/N1brN3/pP1pqp2/6P1/1Bk3PR/2P2K2/2P5/7n

#2

12 + 8

SOLUTION

  • SOUND
  • Sets
    • 1...Qd5+
      • 2.Bxd5#
    • 1...Rxe7
      • 2.Qc6#
    • 1...Rd8
      • 2.Qc6#
    • 1...f5
      • 2.gxf5#
  • Tries
    • 1.Qg6?
      • threat
        • 2.Qd3#
        • 2.Qe4#
      • 1...Qd5+
        • 2.Bxd5#
        • 2.Qe4#
      • 1...Bxb6
        • 2.Qd3#
      • 1...d5
        • 2.Qd3#
      • 1...Sg3
        • 2.Qd3#
      • 1...f5
        • 2.gxf5#
      • 1...Sf2!
    • 1.Qc8?
      • threat
        • 2.Qxa6#
      • 1...Qd5+
        • 2.Bxd5#
      • 1...a5
        • 2.Qa6#
      • 1...Rxe7!
  • Keys
    • 1.Sd5!
      • threat
        • 2.Se3#
      • 1...Qxg4+
        • 2.Rxg4#
      • 1...Qxd5+
        • 2.Qe4#
      • 1...Qf5+
        • 2.gxf5#
      • 1...Qe2+
        • 2.Qxe2#
      • 1...Qe3+
        • 2.Sxe3#
      • 1...Qe4+
        • 2.Qxe4#
      • 1...Kxd5
        • 2.Qxe6#
      • 1...Bxb6
        • 2.Sxb6#
      • 1...Rf7
        • 2.Qc6#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 8
    • REMOVED MATES = 3
  • Sets
    • Q(e);CHECK,OGATE::B(L),XQ(e)
    • R(h);OGATE,XS(J)::QAR2(K)
    • R(h);OGATE::QAR2(K)
    • P(f);OGATE::R(F)+P(E),XP(f)
  • Tries
    • Try
      • Q(K);
      • Threat
        • DUALS(2)
      • Vars
        • B(g);XP(H)::QAB1(K)
        • P(d);N_SPINQ(e)::QAB1(K)
        • S(a);::QAB1(K)
        • P(f);OGATE::R(F)+P(E),XP(f)
      • Refutation
        • S(a);
    • Try
      • Q(K);P_PINB(g)
      • Threat
        • QAB(K),XP(c)
      • Vars
        • Q(e);CHECK,OGATE::B(L),XQ(e)
        • P(c);::QAB(K)
      • Refutation
        • R(h);XS(J)
  • Actual
    • S(J);N_PINQ(e)
    • Threat
      • S(J)
    • Vars
      • Q(e);CHECK,OGATE,P_SPINQ(e),XP(E)::R(F),XQ(e)
      • Q(e);CHECK,OGATE,P_SPINQ(e),XS(J)::QAR2(K)
      • Q(e);CHECK,OGATE::R(F)+P(E),XQ(e)
      • Q(e);CHECK,OGATE::QAB(K),XQ(e)
      • Q(e);CHECK::B(L)+S(J),DCHECK,XQ(e)
      • Q(e);CHECK,OGATE::QAR2(K),XQ(e)
      • K(b);OGATEB,P_SPINQ(e),S_FLIGHT,XS(J)::QAB1(K),XQ(e)
      • B(g);XP(H)::S(J),XB(g)
      • R(h);OGATE::QAR2(K)
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