[Retros] [tros] Happy New Year

Andrew Buchanan andrew at anselan.com
Thu Jan 8 10:50:29 EST 2015


Hi Noam,

Nice mate, mate!

Thanks for your kind words. They say a conjurer should never repeat a trick,
but I was wondering today if I could make a pretty picture from 1959, the
year of my birth, which is not promising factor-wise. I stumbled across
this:

www.janko.at/Retros/d.php?ff=rnbqkbn1/pp1Rppp1/4P3/7p/P7/3p4/1PPPr1PP/1NBQKB
NR
How many ways to reach this diagram at the end of Black's 8th move?

This looks like another "rook-and-pawn opening" but the logic and arithmetic
are rather different from 2015.

Roll on (2^6-1)*2^5 (although we've got a lot of (2^6+1)*(2^5-1) to get
through first)!

All the best,
Andrew.

-----Original Message-----
From: Retros [mailto:retros-bounces at janko.at] On Behalf Of Noam Elkies
Sent: 07 January 2015 23:25
To: retros at janko.at
Subject: Re: [Retros] [tros] Happy New Year

"Andrew Buchanan" <andrew at anselan.com> wrote:

www.janko.at/Retros/d.php?ff=1nbqkbnr/1prpPppp/8/p7/7P/8/PPPpPRP1/RNBQKBN1
How many ways to reach this diagram at the end of Black's 8th move?

That's a wonderful discovery.  I have nothing comparable to offer, but to
avoid interrupting a 10+ year tradition -- and hint at what will be possible
next year -- I offer the following capture-free SPG enumeration where all
the threads contribute to the final pure mate:

White  Rf4 Sb1 Bf6 Qd1 Ke1 Be2 Sg1 Rh1 Pa5 Pb5 Pc2 Pd2 Pe3 Pf2 Pg2 Ph2 Black
Ra8 Sd7 Bc8 Qd5 Kc6 Bc5 Sg8 Rh8 Pa7 Pb7 Pc7 Pd6 Pe6 Pf7 Pg5 Ph7 
www.janko.at/Retros/d.php?ff=r1b3nr/pppn1p1p/2kppB2/PPbq2p2/5R2/4P3/2PPBPPP/
1N1QK1NR

C+ Popeye in <1 second.

Happy Binary Palindrome Year,
--NDE
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