Re: [Bug-gnubg] Tutor mode tests

[Jim Segrave]

On Tue 30 Jul 2002 (18:31 +0100), Ian Shaw wrote:
> Windows build from 020729.
> 
> Settings Same as evaluation (world class chequer & cubes)
> 
> There should be a "Considering moves" message while evaluating my last move.

Should be fixed in today's CVS. I put in a patch to call ProgressStart
followed by Joern's adding a futher patch to block mouse events while
it's working. I was able to store up a bunch of activity while the
machine appeared to be idle when using tutor mode.
 
> When I make a dodgy move, than ask for a hint, the "Considering moves"
> status message appears for ages. Since you've already done this the hint
> should be available straight away.

When the tutor code evaluates a move, after it's completed the
evaluation is deliberately discarded. I did it that way so that if you
were advised that what you'd done was a bad idea and you changed your
move, I wouldn't have screwed up the data for the real move. I'd want
some advice from someone who really understands the internals of the
match record and statistics about how a second evaluation could be
avoided, but at the moment, anything done to make a Tutor advice
decision is lost when the tutor window does/does not pop up. It was
simpler to make the tutor code independant of the rest of the code,
and leave the current behaviour untouched. It certainly would be an
optimisation to save as much as possible of the evaluation for Hints,
and repeated tutor windows. There are some catches:

1) If you are using Analysis evaluation settings for tutor, then the
   data calculated is not what the Hint window wants (unless the
   Evaluation and Analysis settings are the same).

2) As I understand it, when analysing a move, gnubg generates a list
   of all legal moves, and does a first cut evaluation. It then pares
   the list down to n moves and, if need be, drops the nth move and
   inserts yours if your move is bad enough or only looks good in 2 or
   3 ply. Hints has no requirement to keep your tentative move, so the
   lists and evaluation need not be the same for tutor (where a move
   is supplied) and Hint, where only the first few good moves are
   supplied.


> Double and Take decisions don't seem to appear in the analysis window,
> though No Doubles do.

I don't see this on a Unix build from today's (or for that matter any
of the several builds I did over the weekend). Unless you mean the
tutor doesn't work properly for Double/Take - there were some serious
bugs there, fixed Sunday and Monday, although Redoubling tutor advice
is no better than you'd get asking a passer by who'd never played
backgammon :-( This, as it turns out, is harder to get right.

> The missing 1/2 chequer artefacts seem to be much more numerous now.
> 
> Clicking back through the Game Record has sent it absolutely berserk! It
> repeatedly rolled 41 which was my last valid roll and played about 12 moves
> straight through.

Again, I've not seen this.
 
> Subjective impression is that evaluations are taking longer than they used
> to.


-- 
Jim Segrave           address@hidden