Sincerely speaking Chelsea had a good game, is not only you that is impressed, I myself am impressed as well, because they made the match competitive and tough as well. no one really saw the outcome coming, a lot of people believe Arsenal will go for the jugular (direct win), but then considering how tough the game was, a draw is fair enough for both sides.
A draw was very deserved for both teams. From this match, Chelsea were actually able to win because with what they had tried, they played very well and started to gain chemistry with each other. This was important for Chelsea to recover from their downturn. Only one small mistake made by Robert Sanchez had a big influence on the final result.
The positive side for Chelsea in this match is that the defense is quite solid. It looks like Chelsea is a bit less confident when building up from the bottom if the opponent is pressing high. lots of miscommunication between players. Maybe this is a good start to the process. So I can't wait to see the debut of the full Chelsea team later with the addition of Nkunku and Lavia.
Hopefully Chelsea's game like this can continue in the next matches, where the main squad and second squad have even player material.