I think the possible reward percentage is

Also, here's a link to a post that has a lot of good information @splinterlands/splinterlands-ranked-rewards-update
There's a cap on the number of chests that can be earned per day and per season, but I am pretty pleased with the number of chests that I have been able to earn so far this season. The changes really are better for players, but probably not for bot makers and card investors.