[Retros] Double Edgemover 10-piece (kings to original places)

[Mario Richter]

andrew> What is a double edgemover?


feenschach Heft 173 Band XXX Juli-September 2008 
defines double edge-mover as follows:

Doppelrandzueger: Schwarz und Weiss duerfen nur Zuege machen, 
die am Rand enden. Kann eine Partei dies nicht, so ist sie 
maerchenpatt oder maerchenmatt.

i.e. moves have to end on an edge square.

This fits well with e.g. P.I.Olin's A=>B problem, s.
www.softdecc.de/pdb/search.pdb?expression=PROBID='P1017646'


Juha> What is the shortest game to position with
Juha> only 10 pieces with Double Edgemover?  

The job can be done in 18.5 moves:
1.a2-a4 h7-h5 2.a4-a5 h5-h4 3.a5-a6 h4-h3 4.g2xh3 b7xa6 
5.Ra1xa6 Rh8xh3 6.Nb1-a3 Ng8-h6 7.Ra6xa7 Nb8-a6 8.Ra7xa6 Rh3xa3 
9.Ra6xh6 g7xh6 10.b2xa3 Ra8xa3 11.Bf1-h3 Ra3xh3 12.Bc1-a3 Rh3xa3 
13.Qd1-c1 Bc8-a6 14.Qc1xa3 Qd8-a8 15.Qa3xa6 Qa8xh1 16.Qa6xh6 Qh1xh2 
17.Qh6xf8+ Ke8xf8 18.Ke1-f1 Qh2xg1+ 19.Kf1xg1

Best regards,

  mario