[Retros] Last move? records: A new definition and new types

Joost de Heer joost at sanguis.xs4all.nl
Sat Jul 7 11:00:12 EDT 2007


As promised, here is a rough translation of Werner Keym's article in Die
Schwalbe 225.

Last move? records: A new definition and new types
Werner Keym, Meisenheim
Published in Die Schwalbe Heft 225, Juni 2007

One of the best known retro-themes is the economy record for the 'What
was the last move?' stipulation, i.e. the most economic representation
of a uniquely determinable last move. The following economy criteria are
used:
1) The fewest number of pieces (K, Q, R, B, S, P)
2) The fewest number of officers (K, Q, R, B, S)
3) The fewest number of 'heavy' officers (Q, R)
4) The fewest number of queens.

60 Different move types (records) exist:
- K, Q, R, B, S, P move (6 move types)
- K, Q, R, B, S, P captures Q, R, B, S, P (30)
- P moves and promotes to Q, R, B, S (4)
- P captures Q, R, B, S and promotes to Q, R, B, S (16)
- P makes a double move (1)
- P captures en passant (1)
- Castling (2)

Furthermore, there are different types:
Type A: No indication as to who has the move, no king is in check (59
different move types, no e.p.)
Type B: Who has the move is indicated, no king is in check (59 different
move types, no e.p.)
Type C: A king is in check (60 different move types)

This definition of Type C is new! The current definition is: "No
indication as to who has the move, a king may be in check". As a
consequence, a Type A record could also be a Type C record. This has
always been criticised by retro-friends, and on Internet one can find
different definitions. Therefore I proposed the new definition, which
clearly differentiates Type A (without check) and Type C (with check),
and which offers more record possibilities (especially in the fairy
field). The new definition was approved by M. Caillaud, W. Dittmann, A
Frolkin, H. Gruber, A. Kornilov, G. Lauinger, N. Plaksin, M. Richter and
B. Schwarzkopf, and is effective with this publication.

In orthodox chess, the new definition affects only two out of the 178
A/B/C records: The records for KxQ and PxQ=S. Of course #1 (13 pieces)
is still the record for KxQ in Type A (and Type B). The "new" record for
Type C is #2 (14 pieces), originally intended for the related theme
"What is the mating move?". It is more economic than the elder problem
by L. Borodatov (Die Schwalbe 1984, Ka7 Ba5 Be8 Pb4 - Kd8 Ba8 Bb7 Bc8
Pa6 Pb5 Pc6 Pd7 Pe7 Pg7, Last move?). Similarly, #3 (12 pieces) is still
the record for PxQ=S in Type A (and Type B). The "new" record for Type C
is #4, which also has 12 pieces but one officer more.

[The rest of the article is about Duplex Last move and Equal last move]

#1: Luigi Ceriani
problem 1951
1st Prize
3bkS1K/pppprp1p/4p1p1/8/8/8/8/8 (2+11)
+---+---+---+---+---+---+---+---+

| | . | |*B |*K | S | | K |

+---+---+---+---+---+---+---+---+

|*P |*P |*P |*P |*R |*P | . |*P |

+---+---+---+---+---+---+---+---+

| | . | | . |*P | . |*P | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+
Last move? (record for KxQ Type A)

#2: Werner Keym
Die Schwalbe 1990
s1k2Rs1/BppppKp1/1p3p1p/8/8/8/8/8 (3+11)
+---+---+---+---+---+---+---+---+

|*S | . |*K | . | | R |*S | . |

+---+---+---+---+---+---+---+---+

| B |*P |*P |*P |*P | K |*P | |

+---+---+---+---+---+---+---+---+

| |*P | | . | |*P | |*P |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+
Last move? (record for KxQ Type C)

#3: V. Bartolović, Z. Maslar
problem 1957
6th Comm.
2bK1kS1/1pppprp1/5p1p/8/8/8/8/8
+---+---+---+---+---+---+---+---+

| | . |*B | K | |*K | S | . |

+---+---+---+---+---+---+---+---+

| . |*P |*P |*P |*P |*R |*P | |

+---+---+---+---+---+---+---+---+

| | . | | . | |*P | |*P |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+
Last move? (record for PxQ=S Type A)

#4: V.Bartolović, M. Slezinger
problem 1951
1st HM
2bS1b2/1p1ppRp1/2p1k3/2K1p3/8/8/8/8 (3+9)
+---+---+---+---+---+---+---+---+

| | . |*B | S | |*B | | . |

+---+---+---+---+---+---+---+---+

| . |*P | . |*P |*P | R |*P | |

+---+---+---+---+---+---+---+---+

| | . |*P | . |*K | . | | . |

+---+---+---+---+---+---+---+---+

| . | | K | |*P | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+

| | . | | . | | . | | . |

+---+---+---+---+---+---+---+---+

| . | | . | | . | | . | |

+---+---+---+---+---+---+---+---+
Last move? (record for PxQ=S Type C)



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