BRITISH CHESS PROBLEM SOCIETY

#2
a) diagram
b) BPb4 to b5.

a) 1.Qa4? d5 2.Rc6; 1...Kc5 2.Qc6; 1...Kd5!
   1.Qf5? b3 2.Ra4; 1...Kb3 2.Qd3; 1...d5!
   
   1.Ke4 (1...d5+) (2.Q(x)d5)
   
   1...b3           2.Rc6
   1...Kb3          2.Qa2
     
b) 1.Qd2? d5  2.Qc3; 1...Kc5 2 Qd4; 1...b4!
   1.Ke4? (1...Kc5) (2.Qc3) 1...b4 2.Qd5; 1...d5+!
   1.Bd4? Kb3 2.Qc3; 1...Kd5 2.Qa2; 1...b4!
   
   1.Qc7+
    
   1...Kb4,d5 2.Qc3
   1...Kd5    2.Rxd6.

The diagram alone would make a respectable miniature, with flight and self-block changed from try 1.Qf5? to 1.Ke4, while 1.Qa4? adds two new defences giving Q and R mates on c6 (2.Qc6 transferred from 1.Ke4 Kc5). The twin adds four phases, each with two mates, and several changes and transferences, but is damaged by repeated and checking refutations. The content is rich, but less unified and coherent than in the prizewinner.

#2

1.Qf1!                   (2.Sb7 A,Qb5 B,Qa6 C)

1...Sd~ (f4,f6,e7,b6,e3)? 2.ABC
(1...b3!?                 2.Sb7,Qb5 AB);
1...aS~ (b6,b2)!?         2.Qb5,Qa6 BC
1...Sdc3!?                2.Qa6,Sb7 CA
1...Sc7!                  2.Sb7 A
1...Sc5!                  2.Qb5 B
1...Sac3!                 2.Qa6 C

Complete combinative situation of three threats. In The Problemist last January, Ian Shanahan showed nine #2 miniatures with this theme. Can an 8-piece setting have “extreme economy”? The eighth man buys progressions of intelligence – pre-primary correction? – by both BSs. Sd~?, Sdc3!? and Sc7!!, a three-stage progression, allow, respectively, all three threats, one pair, and just one. Meanwhile aS~!? allows another pair of threats, while the two two-stage progressions Sc5! and Sc7! each force another threat from the trio. There is a good unpin key, but a serious defect: the position is C+ without WBf8, which exists only to create a thematically necessary dual after 1...b3: 2.Sb7 (as well as 2.Qb5), completing the third pair of threats after 1...b3.