The terms like A1, A2 are just there to confuse the viewers. The World cup is scheduled in such a way that they have already predicted that only those top 8 team will enter the super eight stage. And each of them is scheduled to play the other 7 team before they enter the knock out stage. For eg:- India will play against SriLanka in the group stage and will play the rest 6 in the super eight stage. You will now get that those terms A2 Vs B2 were all just to confuse the viewers. You can already replace the team name with A2, B2 etc.
