# [Retros] Self-protecting Chess puzzles

Bernd Schwarzkopf schwarzkopf at uni-duesseldorf.de
Sun Jan 27 06:21:19 EST 2008

Hello Eric and other retro friends,

> I re-subscribed a few seconds ago because the two first didn't show in

> my mail-box (nor in the archives). If this

> is old hat, please forgive me. Here is my former 8/I msg. Since then

> I've added a 64 US\$ reward, somewhere on the page]

Unfortunately diagram 1a is empty on my screen.
But the idea is old, look:

Fred Galvin
Journal of Recreational Mathmatics
April 1961
wKd1, Qc1, Rg8, Rh2, Bg3, Bh1, Sa7, Sb7, Pa5,a6,b5,b6,d5,e4,e6,f7
Each man protects exactly one other man; 3 loops.
(bK could be on b3 or h5.)

Jexon J. Secker
The Problemist
May 1980
wKe1, Qa2, Re8, Rg6, Bf1, Bg5, Sc1, Sc5, Pb2,b4,c3,d7,f3,f5,g2,g4
Each man protects exactly one other man; 1 loop.

Colin Vaughan
The Problemist
January 1983
wKg6, Qb7, Rg8, Rh7, Be6, Be7, Sc7, Sd6 (no Pawns)
Each man protects exactly one other man; 1 loop on a 7 x 3-rectangular.

Clive Grimstone
The Problemist
January 1983
wKh6, Qe7, Rf5, Rh8, Bd4, Bg6, Sd5, Se6 (no Pawns)
Each man protects exactly one other man; 1 loop on a 5 x 5-square, 23
squares unprotected (maximum).

Colin Vaughan
Caissas Schloßbewohner
1983
wKg3, Qd5, Ra7, Rb1, Bd4, Bh7, Sf1, Sf4 (no Pawns)
Each man protects exactly one other man; 1 loop, 4 squares unprotected
(minimum).

My article in feenschach 71, November 1984, page 475-476: "Wer deckt wen?"
("Who protects whom?") with reprints of some problems above and:

feenschach 71
November 1984
wKg3, Qf1, Ra4, Rg8, Bc3, Be2, Sc7, Sd7, Pa2,b2,b3,b6,e6,g6,h2,h7
Each man protects exactly one other man; 6 loops.
(bK could be on e4.)