Chelsea claimed the Premier League title last season with a dominant display as Antonio Conte led his team to the title.
Manchester City have done the same this season with a very dominant display, and Conte feels the true test of a side is over a full season.
Chelsea were knocked out of the Champions League in the second round this season, and Conte admits luck has a factor to play in this competition.
“We are talking about two big achievements,” he said. “To win both the Premier League and the Champions League is important, I think they are two important competitions and two difficult competitions to win.
“In the league you have 38 games to show you are the best over the season. In the Champions League, when you reach the last 16, the quarters and semi-finals, one situation – positive or negative – can totally change your future in this competition.
“For this reason, to win the Champions League I think you must be more lucky. You must be good, but at the same time you must be lucky, because one thing – a referee’s decision for example – can change everything.
“During the league, over 38 games, usually the winner deserves to win. The luck is important in every competition, but I think when you have the possibility to play 38 games you can show that you are the best and you deserve to win. In a tournament, sometimes one decision can move your future and sometimes you are lucky or you are unlucky.”