How are the teams balanced in a versus match with less than 8 players?

Question

Suppose I play with 3 other friends a versus match, and would like the teams to be random.

Can I leave all characters unchosen and get a 2 v 2 match? Or the result would be random also? Perhaps all 4 survivors, or infected, or 3 v 1?

Can it be configured somehow to always balance team equally (in terms of number of players)?

Answer 1

In my experience, it will even out the teams with the advantage going to survivors. In other words, if you have 4 players in a lobby and all go random, it will put 2 players as survivor and 2 players as infected. If you have 5 players in a lobby and all go random, it will put 3 on survivors and 2 on infected, with the next player to join filling in the vacant spot to even out the teams.

Answer 2

From some 6-player lobby experiences, the teams have been split 3/3. I have never tried with 4-players, but I'd do one of the 4p modes instead, or Team Versus (premade groups).

The teams are selected once you hit the go button, so if it gives you something screwed up (3v1) you can cancel searching for a server quickly and balance them out.