Problem Display
PID: 23668 (8/8/2p3B1/8/1Nk2K2/Q3P3/8/8 w - - 0 1)

Blumenthal, Oscar

Berliner Schachzeitung, 1871

8/8/2p3B1/8/1Nk2K2/Q3P3/8/8

#2

5 + 2


5454 Near Snap 2007
23 Die Schwalbe 2017

SOLUTION


  • SOUND
  • Sets
    • 1...c5
      • 2.Bd3#
  • Tries
    • 1.Sa2?
      • 1...Kd5
        • 2.Bf7#
      • 1...c5
        • 2.Qd3#
      • 1...Kb5!
    • 1.Sc2?
      • 1...Kd5
        • 2.Bf7#
      • 1...c5
        • 2.Qd3#
      • 1...Kb5!
    • 1.Sa6?
      • threat
        • 2.Qd3#
      • 1...Kd5
        • 2.Bf7#
      • 1...Kb5!
  • Keys
    • 1.Sd5!
      • 1...Kb5
        • 2.Bd3#
      • 1...Kxd5
        • 2.Bf7#
      • 1...cxd5
        • 2.Bd3#
      • 1...c5
        • 2.Qd3#

This anticipates 206673(1925), 936(1993)

FEATURES


  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 1
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
    • P(b);SBLOCK::B(E)
  • Tries
    • Try
      • S(C);
      • Vars
        • K(a);S_FLIGHT::B(E)
        • P(b);SBLOCK::QAB1(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • S(C);
      • Vars
        • K(a);S_FLIGHT::B(E)
        • P(b);SBLOCK::QAB1(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • S(C);
      • Threat
        • QAB1(A)
      • Vars
        • K(a);S_FLIGHT::B(E)
      • Refutation
        • K(a);S_FLIGHT
  • Actual
    • S(C);
    • Vars
      • K(a);S_FLIGHT::B(E)
      • K(a);OGATEB,S_FLIGHT,XS(C)::B(E)
      • P(b);SBLOCK,XS(C)::B(E)
      • P(b);SBLOCK::QAB1(A)


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).