Why does the English Premier League have a double-header week?

English Premier League generally from mid-August to the end of the next year, the end of May, *** more than 9 months, the English Premier League a *** 38 rounds of matches, the game is generally arranged on Saturdays and Sundays, if there is no other tournament, it can be a week of matches, but throughout the season, there are also the FA Cup tournament, the League Cup tournament, and even international soccer tournaments, which will take up Saturdays and Sundays. Premier League if a week a game, will not be able to cause can not complete the entire Premier League schedule in the required time, so in some weeks the Premier League will have to carry out a week of double matches, so as to complete the entire Premier League tournament on time.