Re: [Bug-gnubg] Permit GNU to consider deliberate cube errors

[Ned Cross]

I think this is an interesting idea, but the basic premise seems 
questionable to me. 

The equity values used by bots for given positions are derived from bot 
v bot 'perfect' play.  Accurate cube decisions require accurate 
knowledge of absolute equities.  But in real life, human v human games, 
you can't know the true equities for various reasons.  Will opponent 
handle a recube effectively? Will opponent (or player) move the checkers 
well in the ensuing positions? Will opponent make correct choices 
between going for gammons or playing to save gammons? Will opponent 
incorrectly take or drop cubes now or at a later time?

Trying to subjectively modify the bot's grading scale risks losing the 
integrity of the scale completely.

Making a play that sacrifices equity, then crediting yourself if it 
'works' is playing the results, which we all have learned is not the 
right way to think and improve. It can certainly lead to 'Fancy Play 
Syndrome' where we outplay ourselves by overdoing it.

GNU and Snowie already tell you the parameters for which it is 
appropriate to deviate from the 'proper' cube action ( ie - NoDouble, 
but correct to double if opponent will pass 25% of the time).

For match play, are you using the right MET? What is the true gammon 
rate for matches between you and your opponents? For example I play a 
gentleman in our weekly club tournaments who routinely drops takeable 
cubes, doubles and redoubles late, and does not aggressively pursue 
gammons when there are slight risks of losing the game.  His checkerplay 
is basically strong, better than mine in some ways, worse in others.  
What MET should we use, and how should I grade my cube decisions?  I'm 
not really sure because of how all the variables interact (it's tempting 
to revert to an older MET with a lower gammon rate), so I just keep my 
modern MET in effect.

I think the 'player adjusted' ratings Albert is looking for already 
exist in the scoresheet. 

That said, I DO feel there should be a rating adjustment for ggraccoon's 
insane luck factor!



Albert Silver wrote:
> I had thought of 'filtering' this via a pre-evaluationprocess, where GNU
> would use my proposal to grade the respective players, and if it saw that
> Player 1 would be rated at least Advanced or Expert in cube play then it
> would presume the errors were deliberate (without this, it would obviously
> say the player was much worse since it would be giving full value to the
> deliberate errors). And if the end result was still a very poor grade, then
> it would presume the mutual errors were due to lack of skill. 
>   
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