Question about Crafty vs. gnu

[Sternbach, William [IT]]

Hello,

I downloaded "Crafty" and have a working executable.

I want to let Crafty play gnuches, to see which one will win.
This is very easy, because I can let one be white, and the other black.
As one of them moves, I can manually make that move on the other one.

The problem is, when I run Crafty, the default seems to be for Crafty to
"Play itself", and move for both black and white.

I checked the --help, but couldn't find the correct option.
Do you know what is the command line option for Crafty to set it
in the mode of player vs computer?

Thanks in advance for your help.

- Bill