Very hard question but I'll bet on Chelsea for the following reasons:
1. They have very well balanced 22 players - on each position in the squad they have 2 equaled players or one of them is a little bit better.
2. They don't have players with big egos. In this club, the main targets are the results and nobody cares who will score the goal, who will assist, how the goal was scored, the 11 players on the pitch have only one mission - after the 90 minutes, their team to have score more goals than the opponent. This thing makes this club very solid.
3. Chelsea are not dependent on one or two players. Example - if Salah or Van Dijk get injured - Liverpool are automatically out of the title race. Liverpool are very dependent of these 2 players. If Manchester City loses De Bruyne, Dias or Cancelo, it will be very hard this team to clinch the title for the same reasons above for Liverpool team. Chelsea last month lost Lukaku, Werner, Kovacic, Mount, Kante ( for some of the matches) - their most creative and most important players and what were the results - 5 overall wins and 1 draw and 2 conceded goals ( the draw against Burnley we all know what happened - Chelsea smashed the opponent, but they were not lucky that match).
4. Until now, from the first 11 rounds, Chelsea shows very constant level against the mid-table and bottom table teams - 8 wins and 1 draw. Sir Alex before have told one thing, which is very right - the title in Premier League is winning against these kind of teams, not in the derby matches.
5. Last, but not least - Chelsea has a fantastic tactically coach. From the first day, he shows that he knows how to build this team to lift trophy after trophy. He won the Champions League and Super Cup for such a short time. Tuchel uses the most suitable formation for Chelsea - with 3 central defenders, who are having the following qualities ( higher and faster defenders with very good ball pass ), two half backs ( all of them good in defense and more in offense), two solid CDM ( one very good defensively, the other very good in offense, creating chances for forwards) and 3 attackers.
