[Retros] Promotion to knight a must

andrew buchanan andrew at anselan.com
Sun Dec 17 11:43:46 EST 2006

Hi Andrey,

Thanks for the nice concept. The one that you suggest can indeed be reduced:

PG in 11.0

The solution is the same as yours until White's 10th, then continues:
10.d5 Bb4 11.d6 e1S#.

A shorter example with a different matrix is:

PG in 9.0

With any different promotion choice, Black's last two moves may be
transposed. I can't resist saying I like this PG, and (if no one comes up
with a faster one :-) ) would like to dedicate it to you, Andrey.

However, this is all straying a bit from Hirokaz's theme. A knight promotion
isn't really an *under-promotion*. There is still the question of producing
a promotion to R or B which works as a PG, where the promotion to Q has a
single dual.


-----Original Message-----
From: retros-bounces at janko.at [mailto:retros-bounces at janko.at] On Behalf Of
Sent: 16 December 2006 09:17
To: retros at janko.at
Subject: [Retros] Promotion to knight a must

Hello to all,
Surely this idea can be implemented in a shorter game:
1.Pe2-e3 Pd7-d5 2.Bf1-d3 Pd5-d4 3.Bd3-e4 Pd4-d3
4.Qd1-e2 Pd3xe2 5.Pd2-d4 Qd8-d6 6.Ke1-d2 Qd6xh2
7.Kd2-d3 Qh2xg1 8.Rh1-h5 Qg1-f1 9.Rh5-b5 Pe7-e5
10.Bc1-d2 Bc8-e6 11.Bd2-a5 Bf8-b4 12.Sb1-a3 Pe2-e1=S
Promotion to knight is a must; other promotions destroy game uniqueness (btw
producing only one extra solution resulting from the possibility to
alternate black-s 8th and final moves).
Best wishes,
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