[Retros] Categories for shortest # in SPGs

[fieberg at gcr.com]

New entries (*):

- 6 SPGs from NDE (double checks)
## Ng1/Qd1, ## Ng1/Bf1, ## Ra1/Qd1, ## Ra1/Bf1, ## Rh1/Qd1, ## Rh1/Bf1

- 1 SPGs from myself
# Pb2->N    SPG in 5,5 moves
1 b4 c5 2 bc Qb6 3 cb Nc6 4 ba Rb8 5 a8N Nd8 6 Nc7#


I suggest the following categories for shortes checkmates in SPGs:

I) Checkmates
# Qd1 = Qd1 checkmates
# Pa2 = Pa2 checkmates
Pawns checkmate unpromoted. En passant moves belong to category V.
Castlings are special SPGs within this category.

II) Promotion checkmates
# Pa2->Q = Pa2 promotes to Q and this Q checkmates
The promotee may move. Discovered/double checkmates are not allowed.

III) Discovered checkmates
# Ke1/Qd1 = Ke1 makes the last move and discovers checkmating Qd1
# Pe2/Bf1 = Pe2 moves and discovers checkmating Bf1
Double checkmates are not allowed. En passant moves belong to category VI.

IV) Double checkmates
## Ra1/Qd1 = Ra1 moves with check and discovers Qd1 for doublecheck
## e2Q/Qd1 = Pe2 promotes to Q with check and discovers Qd1 for doublecheck

V) En passant checkmates
# ep-a = Pa2 checkmates en passant

VI) Discovered checkmates by en passant
# ep-c/Qd1 = Pc2 moves en passant and discovers checkmating Qd1


Christoph


I) Checkmates (#)

# P:
a2    SPG in 5,5 - CF 10/02
b2    SPG in 4,5 - CF 10/02
c2    SPG in 5,5 - CF 10/02
d2    SPG in 4,5 - CF 10/02
e2    SPG in 4,5 - CF 10/02
f2    SPG in 4,5 - NDE 10/02
g2    SPG in 4,5 - CF 10/02
h2    SPG in 4,5 - NDE 10/02

# N:
b1    SPG in 4,5 - CF 10/02
g1    SPG in 4,5 - GF 6/96, NDE 10/02

# B:
c1    SPG in 4,5 - CF 10/02
f1    SPG in 3,5 - RS 5/96, CF 10/02

# R:
a1    SPG in 4,5 - GD 5/96, NDE 10/02
0-0-0 SPG in 7,5 - OH 6/96
h1    SPG in 4,5 - CF 10/02
0-0   SPG in 7,5 - OH 5/96

# Q:
d1    SPG in 2,5 - JMS 6/96, JH 6/96


II) Promotion checkmates

# ->Q:
a2    SPG in 4,5 - NDE 10/02
b2    SPG in 4,5 - JMS 10/02
c2    SPG in 4,5 - NDE 10/02
d2    SPG in 4,5 - JMS 10/02, UR 10/02
e2    SPG in 4,5 - GD 6/96, NDE 10/02
f2    SPG in 4,5 - NDE 10/02
g2    SPG in 4,5 - NDE 10/02
h2    SPG in 4,5 - NDE 10/02

# ->R:
a2    SPG in 4,5 - RS 5/96
b2    SPG in 4,5 - JMS 10/02
c2    SPG in 4,5 - NDE 10/02
d2    SPG in 4,5 - JMS 10/02
e2    SPG in 5,5 - CF 10/02
f2    SPG in 4,5 - NDE 10/02
g2    SPG in 5,5 - CF 10/02
h2    SPG in 4,5 - NDE 10/02

# ->B:
a2
b2
c2    SPG in 5,5 - UR 10/02
d2    SPG in 5,5 - GF 5/96, NG 5/96, NDE 5/96
e2    SPG in 5,5 - UR 10/02
f2
g2
h2

# ->N:
a2    SPG in 5,5 - NDE 10/02, UR 10/02
b2    SPG in 5,5 - CF 10/02 (*)
c2    SPG in 5,5 - NDE 10/02, UR 10/02
d2    SPG in 6,5 - UR 10/02
e2
f2    SPG in 5,5 - NDE 10/02
g2    SPG in 5,5 - UR 10/02
h2    SPG in 5,5 - PRö 8/94, NDE 10/02


III) Discovered checkmates

# P/
Pc2/Qd1     SPG in 5,5 - NDE 10/02
Pe2/Qd1     SPG in 5,5 - NDE 10/02

# N/

# B/

# R/

# K/
Ke1/Qd1     SPG in 5,5 - NDE 10/02
Ke1/Bc1     SPG in 5,5 - CF 10/02


IV) Double checkmates

## P/
d2Q/Qd1     SPG in 5,5 - NDE 5/96
d2B/Qd1     SPG in 5,5 - NDE 5/96
e2N/Bc1     SPG in 8,5 - PRa 6/96

## N/
Ng1/Qd1     SPG in 5,5 - RS 6/96, NDE 10/02 (*)
Ng1/Bf1     SPG in 5,5 - NDE 10/02 (*)

## B/

## R/
Ra1/Qd1     SPG in 5,5 - NDE 10/02 (*)
Ra1/Bf1     SPG in 5,5 - NDE 10/02 (*)
Rh1/Qd1     SPG in 5,5 - NDE 10/02 (*)
Rh1/Bf1     SPG in 5,5 - NDE 10/02 (*)


V) En passant checkmates

ep-a
ep-b
ep-c
ep-d
ep-e
ep-f
ep-g
ep-h


VI) Discovered checkmates by en passant

ep-a/
ep-b/
ep-c/
ep-d/
ep-e/
ep-f/
ep-g/
ep-h/



CF = Christoph Fieberg
GD = Gianni Donati
GF = Göran Forslund
JH = Joost de Heer
JMS = Juha M. Saukkola
NDE = Noam D. Elkies
NG = Norbert Geissler
OH = Olli Heimo
PRa = Paul Raican
PRö = Peter Rösler
RS = Richard Stanley
UR = Ulrich Ring