Question to Movefilter

[Frank Berger]

Hi all, 

I have a question about movefilter and the cli.
I want to use GnuBG by the cli, mainly eval and hint.

For eval it works as expected, here an example:

        set lang C
            
        set evaluation chequerplay evaluation plies 2
        set evaluation cubedecision evaluation plies 2

        set matchid UQngABAAIAAE
        set board t20DAAa3OM8AAA 

        eval

BTW I set lang to C so I don’t have to deal with different decimal point/comma 
stuff.

So far so good but when I use hint like here:

        set lang C
            
        set evaluation chequerplay evaluation plies 2
        set evaluation cubedecision evaluation plies 2

        set matchid UQklAVAAQAAE
        set board NrbEBRCD9wYDIA 

        hint

I get only 0-ply evaluation. I found that others setup the movefilter, what 
seems a bit strange to me because in the configuration are already move filters.
When I use the same reasonable movefilters like here:

        set evaluation movefilter 1 0 0 8 0.16

it doesn’t make a difference (I tried 0,16 too) only when I disable the move 
filters like here for 2-ply

        set evaluation movefilter 2 0 -1 0 0 
        set evaluation movefilter 2 1 -1 0 0

so the complete input looks like this:

        set lang C

        set evaluation chequerplay evaluation plies 2
        set evaluation cubedecision evaluation plies 2

        set evaluation movefilter 2 0 -1 0 0 
        set evaluation movefilter 2 1 -1 0 0

        set matchid UQklAVAAQAAE
        set board NrbEBRCD9wYDIA 

        hint

It works as expected. 

I tested it with GnuBG-cli 1.06 on Windows 11 and  GnuBG 1.06 on Linux Mint 
21.3 and both show the described behaviour.

Do I overlook something or is it a quirk?
Thanks in advance for any feedback.


BTW some words why I do this. In chess or Go, you have a very active scene with 
many AIs. In backgammon, there are just three programmes and XG is no longer 
maintained. In my opinion, it is the lack of something like UCI for chess that 
is the reason for this. 
If someone has a great idea for an AI and then implements it, they have to 
programme for another 5-8 years to have a competitive solution. Who does that? 
That's why I want to integrate GnuBG as an AI in BGBlitz to gain experience of 
how such an API should look like. The final "UGI" would certainly look 
different, but gnubg-cli is perfect for learning and it is one of three 
relevant AIs. 

best
Frank