# [Computer-go] Frisbee Go

GonĂ§alo Mendes Ferreira gonmf at sapo.pt
Sat Feb 20 17:51:29 PST 2016

```I don't like it very much, simply selecting only from the valid
neighbors would simplify the rules and shorten the game, but I guess
maybe it does seem similar to what would happen in real life. Are there
other games played with frisbees?

Anyways I propose a frisbee-probability GTP command, it is the bare
minimum to play this:

frisbee-probability (optional)
arguments     float - Value between 0 and 1
effects       Change the active probability of playing intended
intersection.
output        none
fails         syntax error - fails if out of range probability value (<
0 or > 1); unable to change - fails if invoked in the middle of the game
comments      Programs that only support probability 1.0 should not
include this command in their list_commands output.

Sounds about right? It should be the only change necessary for GTP to
start supporting the frisbee.

GonĂ§alo

On 21/02/2016 01:18, John Tromp wrote:
> I don't remember if there was consensus, but can repeat my previous thoughts:
>
>> 1. What happens with plays unintentionally on top of stones or out of
>> bounds?
>
> Converted to involuntary pass.
> Note that a throw must have some positive probability of converting into
> a legal move. This way, infinitely long games have 0 probability.
>
>> 1.1 If converted to passes, do they count towards end of play and
>> scoring phase?
>
> No; only voluntary passes should. Otherwise games would most
> likely end prematurely.
>
>> 2. How are the play probabilities distributed?
>
> They're governed by a single parameter, the hit probability p.
> You hit the target with prob. p, and its 4 neighbours with probability (1-p)/4.
>
> I don't believe there's a single value of p that everyone likes best.
>
> One extreme p=1 is classical Go. The other extreme p=0 is guaranteed
> to miss the target. Other natural choices are p=1/2 or p=1/5.
> (Values in 1/2 < p < 1 seem a little dull to me).
>
> regards,
> -John

```