As Kinnison pointed out, there are only 5 groups to start with. We can't just drop the lowest score per group, because that would leave 25 players, and 25 doesn't divide evenly by 6. A lot of people have been discussing this as if there were 6 groups, but there aren't. I assumed there were, but then I tried to check the standings of all "6" groups to see approximately how many points it will take to stay in the tournament if the lowest 6 scores are dropped. I was surprised to find out there are only 5 groups.
With only 5 groups, it really doesn't seem possible to just drop the lowest score in each group. Maybe we could drop the lowest in each group and one more, but I think it should be the lowest 6 overall. In a competitive group, it could turn out that everyone gets about 40-50 points, where another group could have two or even three people with scores under 20. By dropping the lowest 6 scores overall, the players who are most capable of competing would be kept in the tournament.
BTW, I found out that if the lowest 6 scores are eliminated, then 28 points will be enough to make it to the next round. A player with a lower score than 28 may still have a chance, depending on how things go in the games that haven't been finished. There are a lot of unfinished games in the green group, and there are no standings yet in the cyan group. A lot could happen, but if the lowest 6 scores are dropped, then 28 points clinches a spot in the next round.