#2 Arsenal were simply the weaker side
Arteta's side were superior in the first 45 minutes. However, players such as Alexandre Lacazette and Reiss Nelson missed multiple chances to increase if not double the lead. This proved costly to the team that is yet to keep a clean sheet since beating Bournemouth in October. In the second half, the Arsenal players lost much of their energy and concentration. The Blues found more and more space for themselves, pressured their opponents and forced them into making mistakes. Ultimately, the Gunners finished the match with a low 79% pass accuracy as compared to Chelsea's 83%. Their possession was a low 42% in the loss to the Blues.
As Lampard's side became increasingly dominant, Arteta's side struggled to get out of their own half and contain Chelsea's attack. To put things into perspective, Arsenal recorded only seven shots, five fewer than their draw with Bournemouth on Boxing Day.