[Retros] series SPG

[Richard Stanley]

In the 1996 discussion of short SPG's ending in specified mates, we
also considered series SPG's in which only White moves. Thus we can
try to answer Christophe Fieberg's questions in the series case, in
particular, find the shortest series SPG ending in mate by a specified
unit. Here is a first attempt. None have been computer checked. First
I list the unit together with the least number of moves I could find
(if sound). After this list are the games themselves. Initials such as
(UR) refer to persons who submitted these games in the 1996 discussion.

Ra1: 10
Nb1: 9
Bc1: impossible
Qd1: 5
Ke1: impossible
Bf1: 8
Ng1: ?
Rh1: 8
Pa2: impossible
Pb2: impossible
Pc2: ?
Pd2: ?
Pe2: ?
Pf2: 19
Pg2: 7
Ph2: impossible

Pa2 -> Q: 10
    -> R: 13
    -> B: 14
    -> N: 21

Pb2 -> Q: 11
    -> R: 17
    -> B: 16
    -> N: 22

Pc2 -> Q: 17
    -> R: 17
    -> B: ?
    -> N: 13

Pd2 -> Q: 6
    -> R: 6
    -> B: ?
    -> N: ?

Pe2 -> Q: ?
    -> R: ?
    -> B: impossible
    -> N: ?

Pf2 -> Q: 12
    -> R: ?
    -> B: ?
    -> N: ?

Pg2 -> Q: 12
    -> R: 16
    -> B: 12
    -> N: 13

Ph2 -> Q: 8
    -> R: 8
    -> B: 13
    -> N: 12

***********************************************************************

Ra1: 1.a4 4.ab7 5.bc8N 6.Nxa7 7.Nc6 12. Rxd8#         

Nb1 (TL): 1.Nc3 2.Nd5 3.c3 5.Qxh7 6.Qxg8 7.Qxg7 8.Qe5 9.Nf6#

Qd1 (RS): 1.e3 3.Bh5 5.Qxf7#

Bf1 (RS) 1.a4 3.Rf3 5.e3 6.Bxf7#

Rh1 (RS) 1.h4 4.hxg7 5.Rxh7 8.Rxf8#

Pf2: 1.e4 2.Qg4 4.Qxg8 6.Qb3 11.g8R 13.Rxf7 15.Rc3 19.f7#

Pg2 (UR): 1.e3 3.Qxg7 7.gf7#

Pa2 -> Q: 1.a4 4.ab7 5.ba8Q 6.Qf3 7.e4 9.Bd5 10.Qxf7#

Pa2 -> R: 1.a4 4.ab7 5.Rxa7 7.Rf3 8.d3 10.Bxe7 11.Bxd8 12.Bf6 13.bc8R# 

Pa2 -> B: 1.a4 5.ba8B 7.Bg6 8.e4 10.Qxh7 11.Qxh8 13.Qe6 14.Bxf7#

Pa2 -> N: 1.d3 3.Bxe7 4.Bxd8 6.Bc1 7.e3 9.Qxh7 10.Qxg7 12.Qxa7 13.Qxa8
          15.Qh4 20.a8N 21.Nxf7#   

Pb2 -> Q: 1.b4 4.ba7 5.ab8Q 6.Qxb7 7.Qf3 8.e4 10.Bd5 11.Qf7#

Pb2 -> R: 1.a4 4.Rxd7 6.d5 8.Qxa7 9.Qxb7 11.Qa2 16.bc8R 17.Rxd8#

Pb2 -> B: 1.d4 2.d5 4.Qxa7 5.Qxb7 6.Qb4 7.Qf4 12.bc8B 16.Bxf7#

Pb2 -> N: 1.a4 4.Rxd7 6.d5 8.Qxa7 9.Qxa8 10.Qxb7 12.Qg4 17.bc8N
          18.Nxe7 20.Nxd8 22.Nxf7#

Pc2 -> Q,R: 1.a4 4.Rxd7 7.d6 9.Qxb7 10.Qxc7 12.Qf6 17.cd8Q(R)#

Pc2 -> N: 1.a4 4.Rxc7 5.Rxc8 7.Re3 12.c8N 13.Nd6#

Pd2 -> Q,R (TL, GD): 1.d4 4.dxe7 5.Qd6 6.ef8Q(R)#

Pf2 -> Q: 1.f4 4.fg7 5.gh8Q 6.Qc3 7.d4 9.Bxc7 10.Bxd8 11.Bb6 12.Qc8#

Pg2 -> Q,B (RS): 1.e4 3.Qxg7 4.Qxg8 6.Qb3 11.g8Q(B) 12.Q(B)xf7#

Pg2 -> R: 1.h4 4.hg7 5.gh8Q 7.Qxa7 8.Qxb7 9.Qxc7 11.Qxg8 16.bc8R#

Pg2-> N: 1.h4 4.Rxg7 5.Rxg8 7.Re3 12.g8N 13.Nf6#

Ph2 -> Q,R: 1.h4 4.hg7 7.Rxg8 8.gf8Q(R)#

Ph2 -> B: 1.h4 4.Rxg7 6.Rf3 11.g8B 12.Bxf7#
 
Ph2 -> N (TL) 1.h4 4.hxg7 7.Rxg8 8.Rh8 9.g8N 10.Nh6 11.Nf5 12.Ng7#
 
Richard