14 October 2011

Round and round

Today, I'll show you some continuous helpmates which feature another fascinating way of twinning: except for the initial position, of course, each part of the chess problem results from the previous checkmate position plus an additional alteration.

In April 2010, the British Chess Problem Society (BCPS) organised the 6th European Chess Solving Championship (ECSC) being held in Sunningdale. In conjunction with this event, composing tourneys were being run. The helpmate tourney required twomovers in three or more parts which, taken together as a whole, show one or more round trips. In a round trip a piece leaves a square by a certain route and later in the problem returns to it by a different route. Interestingly, four of the five awarded problems are continuous helpmates. See yourself:

Alexandr J. Semenenko
Waleri J. Semenenko
ECSC Internet Tourney 2010
1st Prize
[1r6/1p4p1/p7/4p3/5bpp/4N3/kp4R1/2nK3n]
  h#2(3+12)  
a) Diagram
b) mate position of a), bK → c7
c) mate position of b), bK → h8
d) mate position of c), bK → g1
e) mate position of d), bK → a3
f) mate position of e), bK → c8
g) mate position of f), bK → h6
h) mate position of g), bK → f3
    a) 1. Nb3 Ne3-c4 2. Na1 Rg2xb2#
b) 1. Ra8 Nc4-d6 2. Kb8 Rb2xb7#
c) 1. Kh7 Nd6-f5 2. Th8 Rb7xg7#
d) 1. g3 Nf5-e3 2. g2 Rg7xg2#
e) 1. a5 Rg2-b2 2. a4 Ne3-c4#
f) 1. Bg5 Rb2-b7 2. Ld8 Nc4-d6#
g) 1. Ng3 Rb7-g7 2. Sh5 Nd6-f5#
h) 1. Kf2 Rg7-g2+ 2. Kf1 Nf5-e3#

Double round trip by the white pieces.

Michael McDowell
ECSC Internet Tourney 2010
2nd Prize
[1K2n3/4Nb2/1n6/p2R2P1/2k5/Pp2p1r1/6Pb/8]
  h#2(6+9)  
a) Diagram
b) mate position of a), bK → e4
c) mate position of b), bK → e6
d) mate position of c), bK → c6
    a) 1. Nb6-a4 Ne7-c8 2. Na4-c3 Nc8-b6#
b) 1. Nc3-e2 Nb6-a4 2. Ne2-f4 Na4-c3#
c) 1. Nf4-g6 Nc3-e2 2. Ng6-e7 Ne2-f4#
d) 1. Ne7-c8 Nf4-g6 2. Nc8-b6 Ng6-e7#

Only knight moves! The white knight chases the black one, each time mating on the latter's diagram square.

Michael Barth
ECSC Internet Tourney 2010
3rd Prize
[8/2ppP3/1b1p1pp1/5kr1/P5p1/1Pp1q1P1/3pr3/5K2]
  h#2(5+13)  
a) Diagram
b) mate position of a), bK → c6
c) mate position of b), bK → d3
    a) 1. Qe3-e5 e8=N 2. Re4 Ng7#
b) 1. Qe5-c5 Ne6 2. Rd5 Nd8#
c) 1. Qc5-e3 Nc6 2. Bd4 Nb4#

Round trip by a "magnetic" black queen with a colleague following her to provide blocks. Judge Chris Feather wondered whether the composer missed the chance to include an additional white knight round trip.

Alexandr J. Semenenko
ECSC Internet Tourney 2010
2nd Honourable Mention
[7r/8/8/8/2qnKN2/8/6R1/1k5r]
  h#2(3+5)  
a) Diagram
b) mate position of a), bK → a7
c) mate position of b), bK → g8
d) mate position of c), bK → h2
    a) 1. Rh8-a8 Nf4-d3 2. Ra8-a1 Rg2-b2#
b) 1. Rh1-h8 Nd3-c5 2. Rh8-a8 Rb2-b7#
c) 1. Ra1-h1 Nc5-e6 2. Rh1-h8 Rb7-g7#
d) 1. Ra8-a1 Ne6-f4 2. Ra1-h1 Tg7-g2#

Round trips by both white pieces and by the black rooks. It's a neat construction without pawns, though it requires additional black material to keep the white king unter control. But the four solutions are "quite the same".

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