Game based conditioning is a very popular and effective method for conditioning work in the team environment. It is however, far from perfect.
At the elite levels players wear heart rate monitors and GPS units to ensure they are working hard enough. At the sub-elite level, this is virtually impossible to monitor.
If you watch a team undertake game based conditioning you will almost certainly see the highly skilled and often fittest players gravitate to the middle of the game, where the majority of the work is done. By the same token the lesser skilled and less fit players will gravitate to the outside and as a result perform more less work. Often they are the ones who need conditioning the most.
The game must be highly structured to ensure all players are working hard enough to receive the benefits.
Another key distinguisher between the elite and the sub-elite in terms of game based conditioning is the skill levels of the players. The players skills must be at a level that facilitate and appropriate work rate. Dropping the ball every 10 seconds will ensure a disjointed, stop-start game and not provide the desired conditioning response.
While game based conditioning sessions are popular at the top, you need to appreciate the levels of the players you are working with and go from there.