Problem Display
PID: 6411 (2N2B2/r1p2p2/1P4RQ/3kpP1N/2p3R1/1n6/r1n1P2K/1B6 w - - 0 1)

Isaev, Leonid Antonovich

2nd Prize, L'Echiquier, 1929

2N2B2/r1p2p2/1P4RQ/3kpP1N/2p3R1/1n6/r1n1P2K/1B6

#2

11 + 9


887 Mate in Two Moves 1931
934 Social Chess Quarterly (The) 1934
3098 FIDE Album (1914-1944) (I) 1971
5454 Near Snap 2007
136 Problem Observer 2015

SOLUTION


  • SOUND
  • Sets
    • 1...Scd4
      • 2.Be4#
    • 1...Sbd4
      • 2.e4#
    • 1...Sc5
      • 2.Se7#
    • 1...cxb6
      • 2.Sxb6#
    • 1...c5
      • 2.Rd6#
    • 1...c6
      • 2.Sf6#
  • Tries
    • 1.Rc6?
      • threat
        • 2.Se7#
      • 1...cxb6
        • 2.Sxb6#
        • 2.Qd6#
      • 1...e4!
    • 1.Rd6+?
      • 1...cxd6
        • 2.Qxd6#
      • 1...Kc5!
    • 1.Re6?
      • threat
        • 2.Sf6#
      • 1...fxe6
        • 2.Qxe6#
      • 1...f6
        • 2.Sxf6#
      • 1...e4!
    • 1.Qd2+?
      • 1...Scd4
        • 2.Be4#
        • 2.e4#
      • 1...Sbd4
        • 2.e4#
      • 1...Sxd2!
    • 1.Qe3?
      • threat
        • 2.Se7#
        • 2.Qe4#
      • 1...cxb6
        • 2.Sxb6#
        • 2.Rd6#
        • 2.Qe4#
      • 1...fxg6
        • 2.Qe4#
      • 1...e4
        • 2.Qxe4#
      • 1...f6
        • 2.Qe4#
      • 1...Scd4
        • 2.Be4#
        • 2.Qe4#
      • 1...Sd2
        • 2.Se7#
        • 2.Qc5#
      • 1...Sbd4
        • 2.Qe4#
      • 1...Sc5
        • 2.Se7#
        • 2.Qxc5#
      • 1...c5
        • 2.Rd6#
        • 2.Qe4#
      • 1...c6
        • 2.Sf6#
        • 2.Rd6#
        • 2.Qe4#
      • 1...Sxe3!
    • 1.Qh7?
      • threat
        • 2.Qxf7#
      • 1...cxb6
        • 2.Sxb6#
      • 1...fxg6
        • 2.Qd7#
      • 1...f6
        • 2.Qd7#
      • 1...Scd4
        • 2.Be4#
      • 1...Sbd4
        • 2.e4#
      • 1...Sc5
        • 2.Se7#
      • 1...c5
        • 2.Rd6#
      • 1...c6
        • 2.Sf6#
      • 1...e4!
  • Keys
    • 1.Qg7!
      • threat
        • 2.Qxf7#
      • 1...cxb6
        • 2.Sxb6#
      • 1...fxg6
        • 2.Qd7#
      • 1...f6
        • 2.Qd7#
      • 1...Scd4
        • 2.Be4#
      • 1...Sbd4
        • 2.e4#
      • 1...Sc5
        • 2.Se7#
      • 1...e4
        • 2.Sf4#
      • 1...c5
        • 2.Rd6#
      • 1...c6
        • 2.Sf6#

This anticipates 51589(1966)

There are these versions: 102480

FEATURES


  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
    • S(b);OGATE,P_PINP(B),SBLOCK::B(A)
    • S(c);SBLOCK::P(B)
    • S(c);SBLOCK::S(J)
    • P(h);XP(G)::S(J),XP(h)
    • P(h);N_GUARD,SBLOCK::R1(H)
    • P(h);SBLOCK::S(F)
  • Tries
    • Try
      • R(H);
      • Threat
        • S(J)
      • Refutation
        • P(f);
    • Try
      • R(H);CHECK
      • Vars
        • P(h);OGATE,XR(H)::QAR1(I),XP(h)
      • Refutation
        • K(e);P-FLIGHT
    • Try
      • R(H);
      • Threat
        • S(F)
      • Vars
        • P(i);OGATE,XR(H)::QAB1(I),XP(i)
        • P(i);::S(F),XP(i)
      • Refutation
        • P(f);
    • Try
      • Q(I);CHECK
      • Vars
        • S(c);P_SPINS(c)::P(B)
      • Refutation
        • S(c);XQ(I)
    • Try
      • Q(I);
      • Threat
        • DUALS(2)
      • Vars
        • P(i);XR(H)::QAB1(I)
        • P(f);::QAB1(I),XP(f)
        • P(i);::QAB1(I)
        • S(c);::QAB1(I)
      • Refutation
        • S(b);P_PINP(B),XQ(I)
    • Try
      • Q(I);
      • Threat
        • QAB(I),XP(i)
      • Vars
        • P(h);XP(G)::S(J),XP(h)
        • P(i);OGATE,XR(H)::QAR2(I)
        • P(i);OGATE::QAR2(I)
        • S(b);OGATE,P_PINP(B),SBLOCK::B(A)
        • S(c);SBLOCK::P(B)
        • S(c);SBLOCK::S(J)
        • P(h);N_GUARD,SBLOCK::R1(H)
        • P(h);SBLOCK::S(F)
      • Refutation
        • P(f);
  • Actual
    • Q(I);
    • Threat
      • QAB(I),XP(i)
    • Vars
      • P(h);XP(G)::S(J),XP(h)
      • P(i);OGATE,XR(H)::QAR2(I)
      • P(i);OGATE::QAR2(I)
      • S(b);OGATE,P_PINP(B),SBLOCK::B(A)
      • S(c);SBLOCK::P(B)
      • S(c);SBLOCK::S(J)
      • P(f);N_GUARD,SBLOCK::S(F)
      • P(h);N_GUARD,SBLOCK::R1(H)
      • P(h);SBLOCK::S(F)


Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) & CSS/Javascript (jQuery, Bootstrap & DataTables).