I am not having any trouble with anything this is just to help people with creating a counter for players which can be filtered as well.
You need these entities and this amount
1 game_zone
1 trigger_multiple
1 math_count
1 other entitie
First you need to make a brush with the texture trigger
2nd you need to make the brush into a entitie (ctrl + t) called game_zone (name it as well) (or something like that)
3rd make a trigger brush entitie called trigger_multiple
4th make a output to the game_zone from the trigger_multiple (onstarttouch)
5th Make a math_counter for the player amount you want if you want it to count more then one count for players make another math_count
6th make a output from the game_zone to the math_count (playercounted (or something like that))
7th make a output from the math_count to the finnal thing you want done.
Here is the example:
http://files.filefront.com/filter+pl.../fileinfo.html