# [Retros] SPGs enabled by A1.3

Francois Labelle flab at EECS.Berkeley.EDU
Sun May 9 15:51:01 EDT 2004

Mario Richter wrote:

> Now if we are interested in x=6 KK positions, we have one extra

> pair of moves to reach a KK position.

Very interesting! In your example you use one x=4 position at ply30, and
then set x=6 for the rest of the search. I could easily use *all* the x=4
positions at ply30. In effect I would be searching with x=4 from ply00 to
ply30, and then with x=6 from ply30 to ply36, which is very easy to do
with my program.

Of course there's nothing special about ply30, and with a computer I can
use a much earlier switchover point. I think that this method is a cheap
way to generate some kind of random sample of all the x=6 KK games (and it
also works for greater values of x of course). This may prove useful,
thanks!

Joost de Heer wrote:

> As far as I know this was already known at the end of the 19th century.

I believe you. But since this KK-massacre is bound to be rediscovered over
and over again, it would be nice to find the earliest reference and add
the problem to the Chess Problem Database Server. Or do you think that
there is no clear composer and that we should call it "folklore"?

> There is one other KK position which can be reached in 16.5 moves,

> but I don't have that one available right now.

You'd know by clicking the ply33 x=3 entry on my Massacre Proof Games
page. :)

http://www.cs.berkeley.edu/~flab/chess/massacre/ply33-x3.html

Let me remind everyone how much computers shine for massacre proof games:
it takes only 1.5 minutes to fully analyze x=3 with my program, and Popeye
can give the full set of solutions to the two KK-SPGs in 30 seconds each.

Francois