In competitive CSGO matches, each player is assigned a role, this helps player to organise and prioritise in game tasks. These roles are especially useful on the Terrorists side of the game. Teams are usually split into fraggers and supporters, lurkers and game leaders.
Entry fraggers will aim to take the first kill around the bomb site area. Supporters take position to cover the fire and provide maximum support for the game. Lurkers are taking their position on the other side of the map to cause confusion and destroy spawners. Sometimes you will find AWPers take place outside of shooting zones, to gather kills from a distance. As the game progresses, game leaders will take lead the strategy and progression of the game.
On the Counter Terrorists side, the process is similar but there are fewer roles to play. Ingame leaders and AWPers will take their stand where as others will aim to destroy the Terrorists side. The team would split to check each bomb site and eliminate the entry fraggers. That’s why you often hear players say “A”, “B” or “rotater”, meaning that they need to check either of the sites or stay in between.
In competitive esports, team will always have one player who performs all of these tasks really well based on their experience, personality and play style. As well as team leaders can usually pivot the game in any direction based on the strategy and on the fly changes. So before jumping to conclusions, or placing any bets on the winning team, make sure you understand each player and their abilities.