Split the 14 day season into 2 phases. First phase (7 days) -> qualifying phase -> Everyone participates just like they did in S1, top 50% of the ranked players receive x amount of tickets(binded) for phase 2.
Second phase (7 days) -> Finals phase -> This week colosseum should have 2 methods of entry, ranked & unraked, unraked -> people play for the regular rewards, ranked -> regular rewards + SR points. In order to enter ranked people need to use 1 ticket/game. Algorithm should be slightly modified, in order to make SR score be additive, meaning people that play all their games from x tickets would have an advantage over people that play less games
This ideas are meant to prevent trolls/ungeared alts to mess with players that are competing & would also stop people from getting good SR score with minimum amount of games played.