Players' quality and form also affect number of chances, opponent's defenders especially... You may get high possession 'cause they are 2-3 stars players, but if they are in good form, they will intercept many passes near the box and will not let your players shoot... I just had a game with opponent creating much more chances than my team in the first half... We had one shot on target in the first half, losing 0-2... At half time, I changed formation, mentality from def to att, focus from middle to mixed, passes from long to short, turned on CA and won the game 4-2... 4 goals from 5 shots on target in the 2nd half...