Clicking the "Details" buttons on the battle screen will show you the number of points you need to be eligible for the next chest. The number of points required for the next chest will grow exponentially. Both season rewards and daily focus rewards have their own details button. The maximum number of chests you can get for your daily focus quest is 30. The maximum number of chests you can get for your season focus quest is 150.
Each type of chest will have a different chance for rewards. The higher the league you play, the better the rewards chances.
For more in-depth information, see the official announcement: Splinterlands Ranked Rewards Update.