Chelsea have not started the season well. They lost the first match against Liverpool. But I was quite satisfied with Chelsea's performance in the first match, even though they were beaten. Chelsea's performance was good. Their match strategy was also quite good. But their performance further deteriorated in the second match against West Ham. They conceded 3 goals and lost the match. And the main reason for Chelsea's poor performance is their poor defence. Had Chelsea's defense been stronger, their performance would have improved. I don't think Chelsea's match strategy is bad. And Pochettino should do his best to tighten up Chelsea's defence.