Rafa has only been in charge for three games, but we can already see what style of play he is hoping to achieve. It's no secret that he likes to play defensively, and so far it looks like he is succeeding in doing this. In his first game in charge, Chelsea made no defensive errors in their first game against Man City and had a 79% tackle rate, they also kept City to eight shots and only one clear chance. The same could be said for their second game against Fulham which had similar results.
Compared to Di Matteo's last game, which Chelsea lost 2-1 to West Brom, who created the same amount of clear cut chances against the Chelsea defense and double the amount of goals scored in one game than in Rafas first two. The defence was starting to look poor under Di Matteo and putting aside the calamity of the West Ham game, Benitez has tightened it up, at a cost. Right now they are focusing too much on defence, which is effecting other aspects of their play. Rafa needs to implement a more balanced tactic, and start using players like Oscar and Hazard to their full potential for this.
The quality of the passing has also decreased, under Di Matteo we had seen a lot of flair in the attack and many probing passes, but with Benitez they seem content to hold the ball in the midfield and at the back. Against Man City, Chelsea passed the ball forward only 36%, and the majority of the time (64%) was spent passing the ball backwards or sideways. As a result the attack is not creating enough chances, despite the many creative players upfront such as Juan Mata and Hazard, if this doesn't change then they will struggle to get goals. It's good to score 6 goals against Nordsjælland and have 16 shots on goal but they need to carry this into the premier league and not repeat what happened against West Ham. Benitez needs to change this soon as so far it could be a lot better, the team will either have to adapt to his tactics or Rafa will have to change his to suit the team.