Re: [gnugo-devel] opening db proposal

[Douglas Ridgway]

On Thu, 21 Oct 2004, Paul Pogonyshev wrote:

> Douglas Ridgway wrote:
> > 
> > [...]
> > 
> > I haven't tried to restrict total number of patterns for its own sake.
> > This might be an issue in the 19x19 even db. If so, we need to decide
> > how big it can be.
> 
> How large is the increase in the binary size for your updated fuseki
> database?

On my machine, a clean cvs gnugo binary takes 4.5M on disk, and compiles
in about 65 s. With the existing fuseki19.db replaced by just the big even
db, no handicap patterns, gnugo occupies 7.9 M on disk and compiles in
about 105 s. I haven't built one with all the new patterns, but I'd guess
the total damage would be about a factor of two in both binary size and
compile time. I don't see an increase in memory footprint, but I'm 
probably just doing something wrong.

> It would be good to test for especially dumb patterns before using this
> database in upstream versions.  May be a non-trivial task given 20,000+
> patterns though.

To a certain extent, this ought to be handled by the strength and
popularity screening: any move which gets played repeatedly by dan level
humans ought not be too bad. Still, it makes sense to look, not least
because the program/training set may be buggy. Here's a couple which don't
look reasonable to me (post 0x13c9b807 and 0x02e29b74), found by looking
for moves with differences in the training set:

+-------------------+
|...................|
|...................|
|...............O...|
|...X...............|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|..*................|
|...X...........O...|
|...................|
|...................|
|...................|
+-------------------+



+-------------------+
|...................|
|...................|
|...*...............|
|...X.....X.....X...|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...................|
|...O...........O...|
|...................|
|...................|
|...................|
+-------------------+


Unfortunately, both of those moves did substantially _better_ than the
alternatives. Since all the players in this set are far stronger than me,
I'm not really qualified to comment.

doug.