[Retros] Pawn to-the-8th-rank mates - response to Francois Labelle's work

andrew buchanan andrew at anselan.com
Mon Dec 25 01:20:57 EST 2006


Thanks for all this wonderful work.

In terms of the original question: "What is a shortest PG for a given
mate?", we now have an answer for 56 of the 88 cases. Yay!

However there is a lot more which you have dug out. You have succeeded in
unifying all the different flavours of this tasks which were coming out. I
really like the taxonomy you developed to support this (although your
notation does my head in - my brain is optimized for letters to be used to
denote piece names or files not mate types :-)

There is one area where alas we appear to disagree. To my mind, the way the
task was specified, there was no mention of minimizing the number of units
captured. It's certainly not something that I considered at all in
composing, or (more importantly) in deciding whether to leave a case alone
after I or someone else had already had found a solution. Following Hiro's
lead, I took the objective criteria to be simply:
(1) number of moves
(2) timestamp
I was happy with this because it left some leeway for creative flair.
Subjective criteria that I then tried to apply where possible (within the
very limited design space) were in no particular order:
(1) no obtrusive promotions (as you have incorporated in your
(2) "model mate" where possible (i.e. each unit which has moved
contributes to the mate, and each flight square for the mated king is only
covered once.)
(3) minimize the number of units in the diagram which are not on
their start squares (to me personally a much more attractive aesthetic
attribute than minimizing the number of units captured).
(4) (related to (2)&(3)) avoid having moved units which don't
contribute to the theme (e.g. avoid having a rook pawn which makes a few
waiting moves while the opponent does something).
(5) other features (tempo, dual avoidance, etc...)

It's not a big deal, but I would be a little uncomfortable for task
compositions to be sidelined for reasons other than a stated design goal. If
I missed an announcement that number of captures *was* an objective
criterion, then I apologize. I know that "minimize captures" has been used
in other tasks before.

There is a broader question then. If the grand database enthusiasm for retro
problems is going to take off, then we will need to record in the database,
not just all the positions, but also the evaluation criteria used, and be
able to associate with each position the values that the criteria take. This
is really a subject for a separate email.

Interesting too the comparison in the different times taken for the three
tools. Popeye starts out strongly, but for 12 ply is overtaken by Euclide.
Could this be expected to apply to other areas of the PG space do you think?


-----Original Message-----
From: retros-bounces at janko.at [mailto:retros-bounces at janko.at] On Behalf Of
Francois Labelle
Sent: 24 December 2006 04:11
To: retros at janko.at
Subject: [Retros] Pawn to-the-8th-rank mates

I computed all "mate by promoting" proof games up to 6.0 moves.


Here are the user-times in seconds: first to compute candidate proof
games, then to verify those candidates with Popeye, Natch, or Euclide.

9 plies: 9 + { 4 P, 31 N, 10 E}
10 plies: 85 + { 23 P, 167 N, 45 E}
11 plies: 4784 + { 781 P, 4926 N, 943 E}
12 plies: 39112 + {11968 P,~16700 N, 3219 E} (Natch time is an estimate)

To extrapolate the computing time, note that adding a move to the pawn
promoting side (going from even ply to odd) is relatively more expensive
than adding a move to the non-mating side (going from odd ply to even).


I'm doing things differently than Hirokaz. Each game appears only *once*,
on one line, and each is fully analyzed for all 4 promotions (NBRQ). The
character-codes used are:

S: Single checkmate by the promoted piece
D: Double checkmate
V: discoVery checkmate
-: no checkmate

A lowercase letter is used (sdv) if promotions are "invisible" (the
material on the board shows no promotion).

The letter is followed by a star (*) if the PG is cooked.

My classification is somewhat detailed, and some merging of categories is
necessary to match Hirokaz's categories.


A line consists of:

- promotion move (ex: axb)
- classification information for N B R Q promotions
- number of moves
- total number of captures
- proof game and author

My comparison to previous records omits the slower opposite color games
and is based on the Dec 14 and Dec 21 summaries by Hirokaz Onoda.

I sorted the proof games in blocks based on the weakest promotion (NBRQ)
that gives a non-cooked checkmate proof game. Within each block I put the
single checkmate games first, followed by proof games with cooks, followed
by the double/discovery checkmates.

Records that I could not improve:
(games in <= 6.0 are optimal, games in <= 6.5 are optimal in length, but
not necessarily in number of captures)

a S - - - 7.0 2 1.c3 b5 2.Qa4 Ba6 3.Qd4 b4 4.a4 b3 5.Ra2 bxa2 6.Kd1
Bxe2+ 7.Kc2 a1=N# (Andrew Buchanan & Nicolas Dupont)
b S - - - 8.0 2 1.a4 c5 2.Ra3 c4 3.Re3 c3 4.d3 cxb2 5.Kd2 Qc7 6.Qe1
Qc3+ 7.Nxc3 a6 8.Nd1 b1=N# (Andrew Buchanan)
c S - - - 8.0 3 1.b4 e5 2.Bb2 Qe7 3.Bd4 exd4 4.e4 d3 5.Qe2 dxc2
6.Qa6 Qxb4 7.Ke2 Qc5 8.Kd3 c1=N# (Andrew Buchanan)
d S - - - 6.0 1 1.d3 e5 2.Kd2 e4 3.Kc3 e3 4.Qd2 exd2 5.b3 Bb4+
6.Kb2 d1=N# (Mario Richter)
e S - - - 6.0 1 1.e3 d5 2.Ke2 d4 3.Kf3 d3 4.Qe2 dxe2 5.g3 Bg4+
6.Kg2 e1=N# (Mario Richter)
f S - - - 7.0 2 1.g3 d5 2.Bg2 Qd7 3.Be4 dxe4 4.d4 e3 5.Qd3 exf2+
6.Kd2 Qf5 7.Ke3 f1=N# (Andrew Buchanan)
g S - - - 8.5 3 1.h4 e6 2.h5 Ke7 3.h6 Kf6 4.hxg7 h5 5.d4 h4 6.Rxh4
Rh5 7.Rg4 Nh6 8.Bxh6 Rf5 9.g8=N# (Andrew Buchanan)
h S - - - 6.0 1 1.h4 g6 2.Rh3 g5 3.Re3 gxh4 4.f3 h3 5.Kf2 h2 6.Qe1
h1=N# (Gianni Donati 1996)
bxa S - - - 7.0 2 1.d4 c5 2.Qd3 c4 3.Qa3 c3 4.d5 cxb2 5.Kd2 Qb6 6.Kc3
Qd4+ 7.Kb3 bxa1=N# (A. Buchanan & H. Onoda)
axb S - - - 8.0 2 1.a4 c6 2.a5 Qxa5 3.Ra4 Qb5 4.Rh4 a5 5.d4 a4 6.Kd2
a3 7.Kc3 a2 8.Qd2 axb1=N# (Richard Stanley)
cxb S - - - 7.0 4 1.a4 c5 2.Ra3 Qa5 3.Rb3 Qxa4 4.d3 c4 5.Kd2 cxb3
6.Kc3 bxc2 7.Qd2 cxb1=N# (Andrew Buchanan)
bxc S - - - 6.0 2 1.e4 a5 2.Ne2 a4 3.Nec3 a3 4.Ke2 axb2 5.Qe1 Ra3
6.Nd1 bxc1=N# (Hirokaz Onoda)
dxc S - - - 8.0 2 1.c3 e5 2.Qa4 e4 3.Kd1 e3 4.Kc2 exd2 5.e3 b6 6.Bd3
Ba6 7.Be4 Bd3+ 8.Kb3 dxc1=N# (Nicolas Dupont)
cxd S - - - 5.5 2 1.d4 f5 2.d5 Kf7 3.d6 Ke6 4.dxc7 d6 5.Qd4 Bd7
6.cxd8=N# (Olli Heimo)
exd S - - - 5.5 2 1.d4 e6 2.d5 Ke7 3.Qd4 Kd6 4.dxe6+ Kc6 5.e7 b5
6.exd8=N# (Olli Heimo)
dxe S - - - 9.0 2 1.f4 e5 2.Kf2 e4 3.Qe1 e3+ 4.Kf3 exd2 5.e4 Be7 6.e5
Bh4 7.e6 Qf6 8.e7 Qe6 9.Bd3 dxe1=N# (Andrew Buchanan)
fxe S - - - 9.0 2 1.c3 e5 2.Qb3 e4 3.Kd1 e3 4.Kc2 exf2 5.e3 h5 6.Be2
h4 7.Bd1 h3 8.Ne2 Rh4 9.Re1 fxe1=N# (Nicolas Dupont)
exf S - - - 5.5 2 1.d4 f6 2.d5 Kf7 3.d6 Kg6 4.dxe7 d6 5.Qd5 Qd7
6.exf8=N# (Andrew Buchanan)
gxf S - - - 5.5 2 1.h4 d5 2.h5 Nd7 3.h6 Ndf6 4.hxg7 Kd7 5.Rh6 Ne8
6.gxf8=N# (Peter Roesler(version) 1994)
fxg S - - - 8.0 5 1.e3 h5 2.Qg4 hxg4 3.Ke2 Rxh2 4.Rxh2 g3 5.Rh6 gxf2
6.Rd6 e6 7.Kf3 Qh4 8.Be2 fxg1=N# (Andrew Buchanan)
hxg S - - - 8.5 5 1.g4 c6 2.g5 Qa5 3.g6 Qxd2+ 4.Qxd2 e6 5.Qh6 Ke7
6.Qxh7 Kf6 7.Qh5 Rh7 8.gxh7 Be7 9.hxg8=N# (Hirokaz Onoda)
gxh S - - - 6.5 2 1.h4 f6 2.h5 Kf7 3.h6 Qe8 4.hxg7 h5 5.e3 h4 6.Qg4
h3 7.gxh8=N# (Andrew Buchanan)
c D - - - 8.5 3 1.d4 e6 2.d5 Qf6 3.d6 Ne7 4.dxc7 d5 5.Qxd5 Bd7
6.Qxb7 Nd5 7.Bd2 Ke7 8.Ba5 Be8 9.c8=N# (Hirokaz Onoda)
e D - - - 8.5 2 1.d4 g6 2.d5 Bg7 3.d6 Kf8 4.Qd5 Bd4 5.Bg5 Kg7
6.Bxe7 Qf8 7.Bd8 Ne7 8.dxe7 Kf6 9.e8=N# (Paul Raican 1996)
f D - - - 9.5 2 1.d4 f6 2.d5 Kf7 3.d6 Kg6 4.dxe7 d5 5.e4 Bf5 6.e5
Nd7 7.exf6 Rb8 8.f7 Ngf6 9.e8=Q Bc5 10.f8=N# (Noam D. Elkies)
bxa D - - - 6.5 3 1.c4 e6 2.c5 Ke7 3.c6 Kd6 4.cxb7 c6 5.Qa4 Kc7
6.Qxa7 Bd6 7.bxa8=N# (Hirokaz Onoda)
axb V V D D 10.5 5 1.b4 c6 2.b5 Qa5 3.b6 Qxd2+ 4.Bxd2 d6 5.Ba5 Bg4
6.Qd4 Nd7 7.Qxg4 O-O-O 8.Qa4 Kb8 9.bxa7+ Ka8 10.Bc7 Rb8 11.axb8=N#
(Hirokaz Onoda)
cxb D - - - 7.5 4 1.d4 f5 2.d5 Nf6 3.d6 Rg8 4.dxc7 d6 5.Qd4 Be6
6.Qxa7 Kd7 7.Qxb7 Ne8 8.cxb8=N# (Hirokaz Onoda)
exd D - - - 6.5 3 1.d4 b5 2.d5 Bb7 3.d6 Be4 4.dxe7 Bg6 5.e4 f6
6.Qxd7+ Kf7 7.exd8=N# (Joerg Varnholt 1996)
dxe D - - - 9.5 4 1.e4 c6 2.e5 Qb6 3.e6 Kd8 4.exd7 e6 5.a3 Bxa3 6.Qf3
Ne7 7.Qxa3 Ng6 8.Qe7+ Kc7 9.Ra6 Re8 10.dxe8=N# (Hirokaz Onoda)
gxh D - - - 7.5 4 1.h4 d5 2.h5 d4 3.h6 Qd5 4.hxg7 Qxg2 5.Rxh7 Qh1
6.Bh3 f6 7.Bd7+ Kf7 8.gxh8=N# (Olli Heimo 1996)

a - S - S 8.5 3 1.b4 d6 2.b5 Bf5 3.b6 Bxc2 4.Qxc2 Kd7 5.Qf5+ Kc6
6.d3 a6 7.Kd2 Ra7 8.bxa7 b6 9.a8=B# (Andrew Buchanan)
b - S - S 9.0 4 1.Nc3 a5 2.Nd5 a4 3.c3 a3 4.Qa4 axb2 5.Qxd7+ Kxd7
6.Kd1 Rxa2 7.Kc2 Ra4 8.Kd3 Re4 9.Ra4 b1=B# (Andrew Buchanan)
c - S - S 9.0 4 1.b3 c5 2.Bb2 Qb6 3.Bd4 cxd4 4.e4 d3 5.Qf3 Qxf2+
6.Kd1 dxc2+ 7.Kc1 Qxf1+ 8.Kb2 Qc4 9.Ka3 c1=B# (Nicolas Dupont)
d - S - S 6.0 2 1.c3 d5 2.Qc2 Qd6 3.Qe4 dxe4 4.Kd1 e3 5.Kc2 exd2
6.e3 d1=B# (Hirokaz Onoda)
e - S - S 5.5 1 1.d4 f6 2.d5 Kf7 3.d6 Kg6 4.dxe7 d5 5.e4 Qd6
6.e8=B# (Norbert Geissler 1996)
f - S - S 6.0 1 1.g3 e5 2.Bh3 e4 3.Kf1 e3 4.Kg2 exf2 5.e3 Qf6 6.Qg4
f1=B# (Nicolas Dupont)
g - S - S 7.0 2 1.Nf3 h5 2.Ne5 h4 3.f3 h3 4.Kf2 hxg2 5.h4 Rxh4
6.Qe1 Rg4 7.Rh8 g1=B# (Hirokaz Onoda)
h - S - S 8.0 2 1.h4 g5 2.Rh3 gxh4 3.Re3 h3 4.g3 h2 5.Bh3 d5 6.Kf1
Qd6 7.Kg2 Bxh3+ 8.Kf3 h1=B# (Andrew Buchanan)
bxa - S - S 8.0 2 1.d3 a5 2.Kd2 a4 3.Kc3 a3 4.Bd2 axb2 5.a4 c6 6.a5
Qb6 7.a6 Qb5 8.a7 bxa1=B# (Andrew Buchanan)
axb - S - S 7.0 4 1.c3 a5 2.Qb3 a4 3.Kd1 axb3 4.a4 Rxa4 5.Ra2 bxa2
6.Kc2 Re4 7.Kd3 axb1=B# (Andrew Buchanan)
cxb - s - S 10.0 4 1.e3 b5 2.Ke2 b4 3.Kd3 b3 4.Qe2 bxc2 5.b4 g6 6.b5
Bg7 7.b6 Bxa1 8.b7 e5 9.bxc8=N Qh4 10.Ne7 cxb1=B# (Andrew Buchanan)
bxc - S - S 8.5 6 1.a4 Nf6 2.a5 Ne4 3.a6 Nxd2 4.axb7 Nb3 5.Qd4 d6
6.Qxg7 Qd7 7.Qxh8 Qc6 8.Qxf8+ Kd7 9.bxc8=B# (Hirokaz Onoda)
dxc - S - S 9.0 2 1.d4 c5 2.Kd2 c4 3.Ke3 c3 4.Nd2 cxd2 5.c3 Qa5 6.Qa4
Qf5 7.Qc6 a5 8.a4 Ra7 9.Ra2 dxc1=B# (Andrew Buchanan)
cxd - S - S 7.5 5 1.b4 Nc6 2.b5 Nd4 3.b6 Nxe2 4.bxc7 Nc3 5.Qg4 e6
6.Qxg7 Bd6 7.Qxg8+ Ke7 8.cxd8=B# (Hirokaz Onoda)
exd - S - S 7.0 2 1.e3 d5 2.Ke2 d4 3.Kd3 Qd5 4.Be2 Qa5 5.Kc4 d3 6.Kb3
dxe2 7.c4 exd1=B# (Andrew Buchanan)
dxe - S - S 6.5 3 1.c4 a6 2.c5 a5 3.c6 a4 4.Qxa4 f6 5.cxd7+ Kf7 6.Qc6
Qe8 7.dxe8=B# (Richard Stanley)
fxe - S - S 7.5 3 1.d4 d6 2.d5 Be6 3.dxe6 Nc6 4.exf7+ Kd7 5.Be3 Qe8
6.Kd2 Nd8 7.Kc1 Kc6 8.fxe8=B# (Noam D. Elkies)
fxe - s - S 9.5 3 1.e4 Nc6 2.Bc4 Rb8 3.Be6 dxe6 4.g4 Kd7 5.g5 Qe8
6.g6 Nd8 7.gxf7 g5 8.Qh5 g4 9.e5 g3 10.fxe8=B# (Nicolas Dupont & Andrew
exf - S - S 5.5 2 1.d4 g6 2.d5 Bh6 3.d6 Kf8 4.dxe7+ Kg7 5.Qd6 Qf8
6.exf8=B# (Goeran Forslund 1996)
gxf - S - S 7.5 3 1.h4 b6 2.h5 Ba6 3.h6 Bxe2 4.hxg7 Bf3 5.Qe2 e6
6.Qa6 Qf6 7.Qc8+ Ke7 8.gxf8=B# (Hirokaz Onoda)
fxg - S - S 9.0 5 1.d3 g5 2.Kd2 g4 3.Ke3 g3 4.Qd2 gxf2 5.g3 e6 6.Bg2
Qf6 7.Bxb7 Bxb7 8.Nf3 Bxf3 9.Rg1 fxg1=B# (Andrew Buchanan)
hxg - S - S 7.5 2 1.e3 h5 2.Qxh5 a6 3.Qc5 Rh5 4.h4 Rg5 5.h5 f6 6.h6
Kf7 7.h7 Ke6 8.hxg8=B# (Olli Heimo & Terho Marlo)
gxh - S - S 7.0 2 1.e3 h5 2.Ke2 h4 3.Kf3 h3 4.Be2 hxg2 5.h4 e6 6.h5
Qh4 7.h6 gxh1=B# (Andrew Buchanan)
bxc - S - S* 8.0 5 1.d3 a5 2.Bg5 a4 3.Bxe7 a3 4.Bg5 axb2 5.Bc1 Qg5
6.Qd2 Qxg2 7.Qc3 Qxf1+ 8.Kd2 bxc1=B# (Andrew Buchanan)
b - D - D 6.5 2 1.c4 e6 2.c5 Ke7 3.c6 Kd6 4.cxb7 c6 5.Qa4 Kc7
6.Qxa7 Na6 7.b8=B# (Hirokaz Onoda)
c - D - D 7.5 3 1.d4 f5 2.d5 Nf6 3.d6 Rg8 4.dxc7 d6 5.Qd4 Be6
6.Qxa7 Kd7 7.Qxb7 Ne8 8.c8=B# (Hirokaz Onoda)
d - D - D 8.5 3 1.e4 c6 2.e5 Qb6 3.e6 Kd8 4.exd7 e6 5.a3 Bxa3 6.Qf3
Ne7 7.Qxa3 Ng6 8.Qe7+ Kc7 9.d8=B# (Hirokaz Onoda)
e - D - D 5.5 2 1.d4 h5 2.d5 Rh6 3.d6 Re6 4.dxe7 f6 5.Qxd7+ Kf7
6.e8=B# (Noam D. Elkies 1996)
f - D - D 7.5 2 1.e4 g6 2.e5 Bh6 3.e6 Kf8 4.exf7 e5 5.Qg4 Qe7
6.Qxd7 Qc5 7.Qe7+ Kg7 8.f8=B# (Hirokaz Onoda)
g - D - D 7.5 4 1.f4 Nf6 2.f5 Ne4 3.f6 Nxd2 4.fxg7 Nf3+ 5.gxf3 f6
6.Qd3 Kf7 7.Qxh7 Qe8 8.g8=B# (Hirokaz Onoda)

a - - S S 6.5 2 1.c4 d5 2.Qb3 Bd7 3.Qh3 Bb5 4.cxb5 Qd6 5.b6 Nd7
6.bxa7 O-O-O 7.a8=R# (Andrew Buchanan & Joost de Heer)
b - - S S 7.0 4 1.d4 c5 2.Bd2 cxd4 3.Ba5 Qxa5+ 4.Nc3 dxc3 5.Qd4 b6
6.Rd1 cxb2+ 7.Rd2 b1=R# (Andrew Buchanan)
c - - S S 5.5 2 1.b4 d6 2.b5 Bf5 3.b6 Bxc2 4.bxc7 Bd3 5.Qa4+ Qd7
6.c8=R# (Hirokaz Onoda)
d - - S S 5.5 2 1.b4 e6 2.Ba3 Bc5 3.bxc5 Qf6 4.c6 Ne7 5.cxd7+ Kf8
6.d8=R# (Richard Stanley 1996)
e - - S S 5.5 2 1.e4 d6 2.Qg4 Bf5 3.exf5 Qd7 4.f6 Kd8 5.fxe7+ Kc8
6.e8=R# (Noam D. Elkies)
f - - S S 6.0 2 1.g3 d6 2.Bg2 d5 3.Be4 dxe4 4.c3 e3 5.Qc2 exf2+
6.Kd1 f1=R# (Richard Stanley 1996)
h - - S S 7.0 2 1.e3 h5 2.Ne2 h4 3.Ng3 hxg3 4.Be2 Rh3 5.O-O Nh6
6.Re1 gxh2+ 7.Kf1 h1=R# (Hirokaz Onoda)
h - - s S 6.5 4 1.h4 g5 2.hxg5 Bh6 3.Rxh6 Nxh6 4.g6 Rg8 5.gxh7 Rg3
6.a3 Ng4 7.h8=R# (Andrew Buchanan)
bxa - - S S 5.5 3 1.c4 d5 2.c5 Qd6 3.c6 Bd7 4.cxb7 Ba4 5.Qxa4+ Nd7
6.bxa8=R# (Andrew Buchanan)
axb - - S S 6.0 3 1.d3 c5 2.Qd2 Qa5 3.Qb4 cxb4 4.Be3 b3+ 5.Nd2 bxa2
6.Rb1 axb1=R# (Joost de Heer)
cxb - - S S 6.0 3 1.d3 c5 2.Qd2 Qa5 3.Qb4 cxb4 4.Be3 b3+ 5.Nd2 bxc2
6.Rb1 cxb1=R# (Andrew Buchanan)
bxc - - S S 4.5 2 1.a4 b6 2.a5 Bb7 3.a6 Qc8 4.axb7 a6 5.bxc8=R#
(Richard Stanley 1996)
dxc - - S S 5.5 2 1.e4 c6 2.e5 Qa5 3.e6 Kd8 4.exd7 e5 5.Qg4 Be7
6.dxc8=R# (Christoph Fieberg 2002)
cxd - - S S 4.5 2 1.d4 g6 2.d5 Bg7 3.d6 Kf8 4.dxc7 d6 5.cxd8=R#
(Hirokaz Onoda)
dxe - - S S 5.5 2 1.c4 e6 2.Qa4 Ba3 3.c5 Kf8 4.c6 Qe8 5.cxd7 c5
6.dxe8=R# (Olli Heimo)
gxf - - S S 4.5 2 1.f4 c6 2.f5 Qc7 3.f6 Kd8 4.fxg7 f6 5.gxf8=R# (Noam
D. Elkies 2002)
hxg - - S S 5.5 2 1.g4 h5 2.g5 Rh6 3.gxh6 g6 4.h7 Bh6 5.h3 Bg5
6.hxg8=R# (Andrew Buchanan & Hirokaz Onoda)
gxh - - S S 5.0 2 1.g3 h5 2.Bh3 h4 3.Bg2 h3 4.Nf3 hxg2 5.Ne5 gxh1=R#
(Mario Richter)
g - - S s* 7.5 3 1.e3 h5 2.Qxh5 Rxh5 3.h4 Re5 4.h5 g6 5.h6 Bg7
6.hxg7 Nh6 7.d4 Nf5 8.g8=R# (Hirokaz Onoda)
h - - S s* 7.5 4 1.e3 h5 2.Qxh5 Rxh5 3.h4 Rg5 4.hxg5 Nh6 5.gxh6 g6
6.h7 Bh6 7.d4 Bg5 8.h8=R# (Hirokaz Onoda)
axb - - S s* 9.0 5 1.a4 c6 2.a5 Qxa5 3.Rxa5 Kd8 4.Rc5 a5 5.b4 axb4
6.Ba3 bxa3 7.Qc1 a2 8.Qa3 Kc7 9.Qh3 axb1=R# (Hirokaz Onoda)
hxg - - S s* 6.5 3 1.e3 h5 2.Qxh5 Rxh5 3.h4 Rf5 4.h5 g6 5.h6 Bg7 6.h7
Bf6 7.hxg8=R# (Hirokaz Onoda)
bxc - - D D 9.5 4 1.c4 d6 2.c5 Bh3 3.c6 Bxg2 4.cxb7 c5 5.Qa4+ Bc6
6.Qxa7 Kd7 7.Bh3+ Kc7 8.Bg4 Na6 9.h3 Rc8 10.bxc8=R# (Hirokaz Onoda)
dxc - - D D 7.5 4 1.e4 c6 2.e5 Qc7 3.e6 Kd8 4.exd7 e5 5.Bc4 Bb4 6.Be6
Bxd2+ 7.Qxd2 Ne7 8.dxc8=R# (Hirokaz Onoda)
cxd - - D D 8.5 2 1.d4 e5 2.d5 Be7 3.d6 Bf6 4.dxc7 d5 5.Be3 Be6 6.Bb6
Kd7 7.Qd4 Kc8 8.Qc5 Nd7 9.cxd8=R# (Hirokaz Onoda)
exd - - D D 7.5 3 1.d4 b6 2.d5 Bb7 3.d6 Bf3 4.dxe7 d5 5.Qd3 d4 6.Qe4
d3 7.Bg5 dxc2 8.exd8=R# (Hirokaz Onoda)
dxe - - D D 8.5 5 1.e4 c6 2.e5 Qc7 3.e6 Kd8 4.exd7 e5 5.Bb5 Bb4
6.Bxc6 Bxd2+ 7.Qxd2 Ne7 8.Kd1 Re8 9.dxe8=R# (Hirokaz Onoda)
exf - - D D 6.5 6 1.d4 c6 2.d5 Qb6 3.d6 Qxb2 4.dxe7 Qxc2 5.Ba3 Qxe2+
6.Qxe2 Nf6 7.exf8=R# (Olli Heimo 1996)
gxf - - D D 7.5 4 1.h4 a5 2.h5 Ra6 3.h6 Rd6 4.hxg7 Rxd2 5.Rxh7 Rd6
6.Qd2 f5 7.Qh6 Kf7 8.gxf8=R# (Joerg Varnholt 1996)
fxg - - D D 7.5 2 1.e4 g6 2.e5 Bh6 3.e6 Kf8 4.exf7 e5 5.Qf3 Qg5 6.Qf6
Qf5 7.Bc4 Bf4 8.fxg8=R# (Hirokaz Onoda)

c - - - S 4.5 2 1.c4 d5 2.c5 Qd6 3.cxd6 Bd7 4.dxc7 Bc6 5.c8=Q#
(Andrew Buchanan)
f - - - S 5.0 1 1.e3 g5 2.Bd3 g4 3.Be4 g3 4.Qg4 gxf2+ 5.Kd1 f1=Q#
(Andrew Buchanan)
g - - - S 7.5 4 1.d3 Nh6 2.Bxh6 gxh6 3.f4 Bg7 4.f5 Bc3+ 5.bxc3 Rg8
6.f6 Rg7 7.fxg7 f6 8.g8=Q# (Hirokaz Onoda)
h - - - S 8.0 2 1.e4 h5 2.Ne2 h4 3.Ng3 hxg3 4.Be2 Rh3 5.O-O Nh6
6.Re1 gxh2+ 7.Kf1 Re3 8.g3 h1=Q# (Hirokaz Onoda)
bxc - - - S 4.5 2 1.a4 c6 2.a5 Qc7 3.a6 Qf4 4.axb7 d6 5.bxc8=Q# (Noam
D. Elkies 2002)
fxe - - - S 5.0 2 1.d3 e5 2.Bg5 e4 3.Kd2 e3+ 4.Kc1 exf2 5.Qe1 fxe1=Q#
(Andrew Buchanan)
gxf - - - S 4.5 2 1.h4 e6 2.h5 Qh4 3.h6 Kd8 4.hxg7 h6 5.gxf8=Q#
(Hirokaz Onoda)
c - - - D 6.5 4 1.b4 d6 2.b5 Bg4 3.b6 Bxe2 4.bxc7 Bxf1 5.Qf3 Kd7
6.Qxb7 Qe8 7.c8=Q# (Hirokaz Onoda)

Records that I could improve (including only reducing the total number of

d - - S s 7.0 1 1.c4 d5 2.Qb3 d4 3.Qh3 d3 4.g3 Qd4 5.Bg2 Qe3 6.dxe3
d2+ 7.Kf1 d1=R# (Richard Stanley 1996)
d - - S s 6.0 2 1.c3 e5 2.Qa4 Qh4 3.Qxh4 e4 4.g4 e3 5.Bg2 exd2+
6.Kf1 d1=R#
g - - S S 6.5 2 1.g4 h5 2.g5 Rh6 3.gxh6 g5 4.h3 Bg7 5.hxg7 Nh6 6.h4
Nf5 7.g8=R# (Andrew Buchanan)
g - - S S 6.0 3 1.e3 d5 2.Bd3 Bg4 3.Be4 dxe4 4.Nf3 exf3 5.h3 fxg2
6.Rh2 g1=R#
exd - - S S 5.5 3 1.d4 g6 2.d5 Bg7 3.d6 Be5 4.dxe7 d6 5.Qxd6 Be6
6.exd8=R# (Hirokaz Onoda)
exd - - S S 5.5 2 1.d4 Na6 2.d5 Nc5 3.d6 Na4 4.dxe7 d5 5.Bg5 d4
fxe - - S S 6.5 2 1.e4 d6 2.e5 Bf5 3.e6 Be4 4.exf7+ Kd7 5.Bb5+ Kc8
6.Ba4 Qe8 7.fxe8=R# (Andrew Buchanan)
fxe - - S S 6.0 2 1.d4 e5 2.Qd3 Qh4 3.Bg5 e4 4.Nd2 e3 5.O-O-O exf2
6.Re1 fxe1=R#
exf - - S S 5.5 3 1.d4 g6 2.d5 Bg7 3.d6 Bxb2 4.dxe7 Bg7 5.Ba3 Bf8
6.exf8=R# (Andrew Buchanan)
exf - - S S 5.5 2 1.d4 Na6 2.d5 Nc5 3.d6 Na4 4.dxe7 c5 5.Qd6 Qb6
fxg - - S S 6.5 5 1.h4 g5 2.hxg5 Bg7 3.Rxh7 Kf8 4.Rxg7 Rh5 5.g6 Rd5
6.gxf7 e5 7.fxg8=R# (Andrew Buchanan)
fxg - - S S 6.0 2 1.f4 e5 2.Nf3 e4 3.Rg1 exf3 4.e4 Bc5 5.Be2 f2+
6.Kf1 fxg1=R#
c - - S s* 6.5 2 1.c4 b6 2.Qb3 Bb7 3.Qxb6 cxb6 4.c5 Qc7 5.c6 Qd6
6.c7 Bc6 7.c8=R# (Hirokaz Onoda)
c - - S s* 6.0 3 1.b3 c5 2.Bb2 Qa5 3.Bd4 cxd4 4.Qc1 d3 5.Qa3 dxc2
6.Qxa5 c1=R#
bxc - - S s* 5.5 5 1.d4 c6 2.d5 Qb6 3.Qd4 Qxd4 4.dxc6 Qxb2 5.cxb7 Qb5
6.bxc8=R# (Andrew Buchanan)
bxc - - S s* 5.5 3 1.c4 b5 2.cxb5 c5 3.b6 c4 4.b7 Qb6 5.Qb3 Qxb3
cxd - - S s* 6.5 4 1.d4 g6 2.d5 Bg7 3.d6 Kf8 4.dxc7 d6 5.Qxd6 exd6
6.Bd2 Ne7 7.cxd8=R# (Andrew Buchanan)
cxd - - S s* 6.0 3 1.g3 d5 2.Bg2 d4 3.Kf1 Qd5 4.Bxd5 d3 5.Bg2 dxc2
6.d3 cxd1=R#

d - - - S 5.0 2 1.e3 d5 2.Bc4 dxc4 3.Qf3 c3 4.Ke2 cxd2 5.c3 d1=Q#
(Andrew Buchanan)
d - - - S 5.0 1 1.e3 c5 2.Ba6 c4 3.d3 c3 4.Qd2 cxd2+ 5.Kf1 d1=Q#
cxd - - - S 4.5 3 1.e4 e6 2.e5 Bd6 3.exd6 Kf8 4.dxc7 d6 5.cxd8=Q#
(Gianni Donati 1996)
cxd - - - S 4.5 2 1.b4 e5 2.b5 Ba3 3.b6 Kf8 4.bxc7 b5 5.cxd8=Q#
hxg - - - S 6.5 4 1.g4 h5 2.g5 Rh6 3.gxh6 g6 4.h7 Bh6 5.e3 Bxe3
6.fxe3 f5 7.hxg8=Q# (Hirokaz Onoda)
hxg - - - S 6.0 3 1.g3 h5 2.Bh3 h4 3.Be6 hxg3 4.h3 Rh4 5.Rh2 gxh2
6.f3 hxg1=Q#

New tasks:
(But most of these play on the visibility of promotions which wasn't a
focus before.)

c - - S s 5.5 3 1.b4 d5 2.b5 Bg4 3.b6 Bxe2 4.bxc7 Bxd1 5.Bb5+ Qd7
c - - s S 6.0 3 1.b3 d5 2.Bb2 Bd7 3.Bxg7 d4 4.c3 d3 5.Qc2 dxc2
6.Bxh8 c1=R#
d - - s S 6.0 3 1.e3 c5 2.Qf3 c4 3.Qxb7 c3 4.Qxa8 Ba6 5.Be2 cxd2+
6.Kf1 d1=R#
f - - s S 6.0 3 1.e3 g5 2.Ba6 g4 3.Bxb7 g3 4.Bxa8 Ba6 5.Qg4 gxf2+
6.Kd1 f1=R#
bxa - - s S 6.0 6 1.b4 a5 2.Ba3 axb4 3.Qc1 Rxa3 4.Nxa3 bxa3 5.Qb2
axb2 6.Kd1 bxa1=R#
bxc - - S s 5.5 5 1.d4 c5 2.dxc5 Nf6 3.Qxd7+ Qxd7 4.c6 Qd3 5.cxb7
Nfd7 6.bxc8=R#
bxc - - s S 4.5 3 1.a4 c5 2.a5 c4 3.a6 Qa5 4.axb7 Qxa1 5.bxc8=R#
bxc - - s s 6.0 5 1.b4 a5 2.Bb2 axb4 3.Qc1 Ra3 4.Bxa3 b3 5.Bxe7 b2
6.Bxd8 bxc1=R#
dxc - - S s 6.0 3 1.c3 e5 2.Qa4 Qh4 3.Qxh4 e4 4.g4 e3 5.Bg2 exd2+
6.Kf1 dxc1=R#
dxc - - s S 6.0 4 1.b3 c5 2.Bb2 c4 3.Bxg7 c3 4.Bxh8 Bh6 5.Qc1 cxd2+
6.Kd1 dxc1=R#
cxd - - S s 5.5 5 1.d4 e5 2.dxe5 Nh6 3.Qd6 Bxd6 4.exd6 Kf8 5.dxc7 Kg8
cxd - - s S 5.5 3 1.b4 g5 2.b5 Bg7 3.b6 Bxa1 4.bxc7 Bg7 5.Bb2 Kf8
exd - - S s 6.0 4 1.b3 d5 2.Ba3 d4 3.Bxe7 d3 4.Bxd8 dxe2 5.d4 Bg4
6.d5 exd1=R#
exd - - s S 5.5 4 1.f4 Nf6 2.f5 Ne4 3.f6 Nxd2 4.fxe7 Nb3 5.Bg5 Nxa1
fxe - - S s 6.0 3 1.d4 e5 2.Qd3 Qg5 3.Bxg5 e4 4.Nd2 e3 5.O-O-O exf2
6.Re1 fxe1=R#
exf - - s S 5.5 4 1.d4 Nc6 2.d5 Nd4 3.d6 Nxe2 4.dxe7 Ng3 5.Qd6 Nxh1
gxf - - S s 6.0 5 1.Nc3 d5 2.Ne4 dxe4 3.f3 Qd3 4.cxd3 exf3 5.Qc2 fxg2
6.Kd1 gxf1=R#
gxf - - s S 5.5 4 1.f4 c6 2.f5 Qb6 3.f6 Qxb2 4.fxg7 Qxa1 5.Ba3 e5
gxh - - s S 5.5 3 1.h4 Nh6 2.h5 Nf5 3.h6 g6 4.Rh5 Bg7 5.hxg7 gxh5
exd - - S s* 6.0 4 1.b4 d5 2.Bb2 Bg4 3.Be5 d4 4.Bxc7 d3 5.Bxd8 dxe2
6.Bc7 exd1=R#

c - - - s 4.5 3 1.e4 d5 2.e5 Qd6 3.exd6 Bg4 4.dxc7 Bxd1 5.c8=Q#
d - - - s 6.0 3 1.e3 d5 2.Bc4 dxc4 3.Kf1 Qd3+ 4.cxd3 c3 5.Qb3 cxd2
6.Qa3 d1=Q#
e - - - S 5.5 2 1.e4 d5 2.Qe2 Bf5 3.exf5 Qd6 4.f6 Kd7 5.fxe7 f5
f - - - s 5.5 3 1.d4 e5 2.dxe5 Ba3 3.Qd6 cxd6 4.e6 Qc7 5.exf7+ Kd8
bxc - - - s 5.5 4 1.a4 d5 2.a5 Bg4 3.a6 Bxe2 4.axb7 Bxd1 5.Ba6 Qc8
dxc - - - S 6.0 2 1.c3 e5 2.Qa4 e4 3.Kd1 e3 4.Qg4 exd2 5.a4 Ba3 6.b3
dxc - - - s 6.0 4 1.b3 c5 2.Ba3 c4 3.Bxe7 c3 4.Bxd8 Ba3 5.Qc1 cxd2+
6.Kd1 dxc1=Q#
cxd - - - s 5.5 3 1.d4 c5 2.d5 Nc6 3.dxc6 e5 4.Qd6 Bxd6 5.c7 Kf8
exd - - - S 5.5 3 1.d4 Na6 2.d5 Nc5 3.d6 Na4 4.dxe7 d5 5.Qxd5 c5
fxe - - - s 5.5 3 1.e4 d5 2.Qg4 Bxg4 3.e5 Kd7 4.e6+ Kc8 5.exf7 Qe8
exf - - - S 5.5 2 1.d4 Nf6 2.Bh6 g5 3.d5 Bg7 4.d6 Rf8 5.dxe7 Bh8
gxf - - - s 5.5 5 1.d4 e5 2.dxe5 f6 3.Qd6 cxd6 4.exf6 Qc7 5.fxg7 Kd8
c - - s*S 6.0 4 1.b4 a5 2.Ba3 axb4 3.Qc1 Rxa3 4.Qxa3 b3 5.Qa5 bxc2
6.a3 c1=Q#
g - - s*S 6.0 3 1.g3 h5 2.Bh3 h4 3.Bg2 h3 4.Nf3 hxg2 5.Nd4 Rxh2
6.Rxh2 g1=Q#
h - - s*S 6.0 4 1.e3 h5 2.Ne2 h4 3.Ng3 hxg3 4.Be2 Rxh2 5.Rxh2 gxh2
6.Kf1 h1=Q#
bxc - - s*S 5.5 3 1.a4 b5 2.axb5 c5 3.Ra5 Qxa5 4.b6 Qb4 5.b7 a5
gxh - - s*S 5.5 6 1.h4 g5 2.hxg5 h6 3.Rxh6 Nxh6 4.gxh6 Bg7 5.hxg7 Na6
e - - - D 5.5 2 1.d4 e5 2.d5 Ba3 3.d6 Ne7 4.dxe7 f6 5.Qxd7+ Kf7

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