[p3tsin]

Well, no... This is how I'd do it:

RandomizeTeams() {
    decl players[MAXPLAYERS], i
    new max_clients = GetMaxClients()
    new count, bool:team

    for(i = 1; i <= max_clients; i++) {
        if(IsClientInGame(i)) {
            players[count++] = i
        }
    }

    SortIntegers(players,count,Sort_Random)

    for(i = 0; i < count; i++) {
        ChangeClientTeam(players[i],team ? TEAM_RED : TEAM_BLUE)
        team = !team
    }
}