 Complete the following phrase:  In the knockout stage, if a match is level at the end of 90 minutes of normal playing time, extra time will be played two periods of 15 minutes each. If still tied after extra time, the match will be decided by a penalty shoot-out to determine the winner. The video assistant referee VAR system will be used from the quarter-finals onwards. For the first time since a knockout stage was added to the competition in 