Arsenal fan tv is going to be a classic.
I'm not sure if the actual central defenders are to blame in this half. For Arsenal, I reckon Mustafi and Sokratis (one of them is shit and the other one is slow) were not protected enough by Xhaka (arguably the worst player on the pitch) and Guendouzi (who's done alright given his inexperience) so the Chelsea midfield found it easy to put balls between the backline and Cech. Saying this, Arsenal's right seriously struggled much more than their left.
For Chelsea, most if not all of Arsenal chances were created from crosses made from the byline and pulled back towards the penalty spot. Again it's the midfielders' job to follow the movement. Can't blame Rüdiger (who I rate as highly as Mustafi) and David Luiz. Azpi and Alonso moreso but Chelsea aren't defending as a unit and it shows.
Been a great watch though. More of the same in the second half please.