[XBoard-devel] Desired behavior: POV of scores

[h.g. muller]

There was some discussion on TalkChess on the Point Of View that should
be used for score reporting. Although it is not mentioned in the specs,
de-facto standard is that engines always report scores from the POV of the
side to move.

This leads to a bit of a chaotic situation (which I do not want to address at
this moment in case the engine is pondering), as some engines ponder the
position after a speculative expected opponent move (so that their ponder
scores are from the POV of the side they are actually playing), while others
ponder the position as it is, and report scores from the POV of the opponent.

What I do want to address is score reporting while the engine is thinking /
analyzing. There are engines which systematically report scores from the
white POV. In my opinion, this is a non-compliancy, but to be able to 
accomodate
such engines in cases where the score is used for adjudication, WinBoard
provides the option "-first(second)ScoreIsAbs true|false". In 4.4.1, 
setting this
option causes a score flip in MachineBlack mode, or for the engine playing 
black
in TwoMachines mode.

Now it seems to me that it should be counted as a bug that this is not extended
to other modes where the engine is evaluating a black move: IcsPlayingBlack
in zippy mode, and the various modes where an engine is analyzing (AnalyzeMode,
AnalyzeFile or IcsObserving in zippy mode when the engine is analyzing the
observed game), and black has the move. Also there the standard is that 
engines
should report from the POV of the side to move, so that engines that report 
from
the white POV need their score flipped to correct their non-compliancy.

Do we agree about that?

(In these new mode the score is not really used for anything like 
adjudication,
so it might not seem to matter that much, but the score is presented to the 
user,
and one of the major reasons why users would use AnalyzeMode at all, so I guess
this should count as a pretty important use.)

Now a second, and independent question is this:

Once all engines are compliant w.r.t. score reporting, or can be made 
compliant with
the ScoreIsAbs option, what POV do we want to use for presenting this score 
to the
user. It seems that the POV of the side to move, which is used now, is 
compatible
with the EPD standard. There seem to be many users that hate it, though. Should
this be a user-settable option? We could, for instance, have a check box in the
Engine-Output window that would enable the user to select white POV or stm POV.

Is this worth having?