RE: [Bug-gnubg] Bearoff dB position, few questions

[Massimiliano Maini]

address@hidden
wrote on 26/06/2009 15:34:56:

> About the side question (purely theoretical):
> 
> I think that there are many different equities and winning chances
> implied in match play. If we want to keep things clear, the GWC
> ***should *** not depend on the score. What has the match score to
> do with the possibilities that a given position leads or not to
> winning the game where it occurs? Clearly nothing. 
> It is absolutely necessary here to distinguish between Match Winning
> Chance (win or loose) and Game Winning Chances (win/loose
> simple, gammon, backgammon).

Win/lose may be the same across different scores,
but for sure gammon
and backgammon percentages are not.

> I would find it ***very*** helpful, at least
for a beginner like 
> myself that would also like to have a theoretical perspective on
> the game and/or software, if in the different dialog boxes of GnuBG,
> it had been made explicit whether, in match play, the term
> “equity” refers to match equity or the current game equity (as if
it
> were a money game). Currently my understanding is that money
> game equity is completely irrelevant to match play, and that in a
> match situation, in every window, the term equity refers to match
> equity (even if expressed as NEMG), except when explicitly otherwise
> mentioned.  Am I wrong about this?

For match, the real thing is MWC.
Conversion of MWC into EMG equities is done only for
the purpose of 
providing an estimation of the magnitude of the gap
betwen two plays
in a manner that it is as independent as possible
from the match score.

A 1% MWC error at 0-0 to 15 could easily be a 10%
error at double match
point. On the other hand, the normalization to EMG
equities will make
the two errors similar in magnitude.

MaX.