The programs that explicitly wanted to identify each other started 2-0-2 in the first three rounds (and had no way to tell which of the three they were facing). An arbitrary opening sequence seems like the standard method, in general (and clearly 2-0-2 was not an optimal choice).
Other bots may have used different starting sequences to identify themselves, but all such bots died quickly.
My bot made no attempt to identify itself, to itself or to others, since it would self-cooperate anyway.
but how did the three programs identify each other?
The programs that explicitly wanted to identify each other started 2-0-2 in the first three rounds (and had no way to tell which of the three they were facing). An arbitrary opening sequence seems like the standard method, in general (and clearly 2-0-2 was not an optimal choice).
Other bots may have used different starting sequences to identify themselves, but all such bots died quickly.
My bot made no attempt to identify itself, to itself or to others, since it would self-cooperate anyway.