MESON Chess Problem Database

Problem Display
PID: 157784 (2NR4/p2N1Kp1/2p5/3k4/P2pp2R/b1P2p2/q1Qn4/8 w - - 0 1)

Melvin, Herbert A ('Hamel' or Zaak, HA)

The Problemist, 1973

2NR4/p2N1Kp1/2p5/3k4/P2pp2R/b1P2p2/q1Qn4/8

#2

8 + 10

15148 Sadier Collection 2016

SOLUTION

  • SOUND
  • Sets
    • 1...Sb1
      • 2.Qxa2#
    • 1...Sf1
      • 2.Qxa2#
    • 1...Sb3
      • 2.c4#
    • 1...Sc4
      • 2.Qxe4#
    • 1...e3
      • 2.Rxd4#
  • Tries
    • 1.Qxa2+?
      • 1...Sb3
        • 2.Qxb3#
      • 1...Sc4!
    • 1.c4+?
      • 1...Sxc4
        • 2.Qxe4#
      • 1...Qxc4!
  • Keys
    • 1.Rxe4!
      • threat
        • 2.Rxd4#
      • 1...Kc4
        • 2.Rxd4#
      • 1...Sxe4
        • 2.Qxa2#
      • 1...dxc3
        • 2.Qd3#
      • 1...c5
        • 2.Se5#
      • 1...Qc4
        • 2.Re5#
      • 1...Bc5
        • 2.Sdb6#
      • 1...Sb3
        • 2.c4#
      • 1...d3
        • 2.Rd4#
        • 2.Qxd3#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 6
    • REMOVED MATES = 4
  • Sets
    • S(b);N_GUARD::QAB(A),XQ(a)
    • S(b);N_GUARD,S_CUTQ(a)::P(B)
    • S(b);N_GUARD,SBLOCK::QAB1(A),XP(f)
    • P(f);OGATE::R1(D),XP(e)
  • Tries
    • Try
      • Q(A);CHECK,XQ(a)
      • Vars
        • S(b);N_GUARD,P_SPINS(b)::QAB(A),XS(b)
      • Refutation
        • S(b);P_SPINS(b)
    • Try
      • P(B);CHECK
      • Vars
        • S(b);SBLOCK,XP(B)::QAB1(A),XP(f)
      • Refutation
        • Q(a);XP(B)
  • Actual
    • R(D);XP(f)
    • Threat
      • R1(D),XP(e)
    • Vars
      • K(g);P_SPINP(e),S_FLIGHT::R1(D),XP(e)
      • S(b);N_GUARD,SBLOCK,XR(D)::QAB(A),XQ(a)
      • P(e);OGATEB,XP(B)::QAR2(A)
      • P(h);SBLOCK,S_CUTB(c)::R(H)+S(E)
      • Q(a);SBLOCK::R1(D)
      • B(c);SBLOCK::R(H)+S(E),DCHECK
      • S(b);N_GUARD,S_CUTQ(a)::P(B)
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