I think it may take few hours to check all the predictions but I've just did a quick manual check and as I see there is no members predicted more than 10 correct teams but there are many members predicted 10correct teams.
Most of them wrong on group F where they predict Portugal and Austria.
P.S : I could be wrong on this, so lets just wait for the official announcement from OP or sportsbet.
I don't think too many people predicted 10 teams correctly because 1st and 2nd place is important in this game. I predicted right almost all teams which qualify but order was wrong.
No, it's not the main requirement You only need to select the top 2 teams in each group no matter who is ranked 1st and 2nd
If you managed to choose 10 teams to qualify for the round of 16 then you are among the winners of this promotion