Stock vocative in
辩论赛 (debate competitions), where
对方辩友 ('opposing debater') and
我方辩友 ('my-side debater') are the formal forms of address. The genre exploded in the 1990s with
国际大专辩论赛 (the International College Chinese Debate Championship) on CCTV, and
辩友 stuck as a slightly grandiose shorthand. Similar structure to
网友 (netizen),
战友 (comrade-in-arms).
