http://mp1st.com/2012/05/22/counter...s-major-update-now-supports-up-to-30-players/Counter-Strike: Global Offensive now supports 15v15 on official maps.
Increasing the player limit has been “one of the most requested map features,” according to the latest dev blog. “The spawn locations have been prioritized to accommodate various numbers.”
The developers noted, “server operators, if you allow for more players, you may want to play with the bot quota number to find a number that works best with your server.”