Re: [Bug-gnubg] Re: Bug-gnubg Digest, Vol 97, Issue 5

[Jim Segrave]

On Fri 17 Dec 2010 (18:59 +0100), Frank Berger wrote:
> > Maybe I'm missing something here, but gnubg's luck figures apply to
> > each player's rolls separately. Rolling a joker for player A can add
> > 3% to his luck, it does not take 3% away from his opponent's luck, so
> > there's no reason to assume they should be equal.  One player, playing
> > perfectly, could have a fairly low luck rating if the spread in
> > possible equities is small for all his rolls. Another player could
> > have a high luck rating if he rolls the least of all evil rolls (the
> > average roll leaves two blots, his roll only leaves one). He's lucky,
> > but he's not all that lucky, he still has a blot. Luck is the measure
> > of getting the most favourable of all possible rolls, not a measure of
> > game winning chances in and of themselves.
> 
> the luck of the player doesn't have to be the same, but the addition of the 
> luck of both players could be calculated, in a perfect world, 
> by the skill of the players. Assume a game is a random walk on a line, where 
> the players start a certain position. Let's say you win against me in 52% of 
> the games. To win (the 1-pt match) you need 0.48 luck to move from .52 to 1.0 
> whereas I need .52 luck to go from .52 to 1.0, therefore the the sum of your 
> luck - my luck should be .52 if I win and .48 if you win.

That's true, but the luck figure gnubg is assigning to a roll and
accumulating over a match or game isn't that figure. It's a figure for
each player of how much better or worse an individaul roll is against
the average 'value' of all possible rolls in that position. I'm pretty
sure t's not necessarily true that two 'perfect' players will always
have the player with the greater gnubg luck figure as the winner,
although the exceptions, I suspect, are rare.

-- 
Jim Segrave           address@hidden