Afghanistan can't crash today. This would be a big dent to their confidence otherwise. If SL lose, it would still not matter as they have been on a losing streak since eternity and next world cup they wont qualify unless there are drastic changes
DL method can be easily called as the most confusing formula in a sports event. Basic rule behind DL method is the calculation of "available resources" to the batting team. The formula considers balls left and wickets in hand as the resources. From there it calculates how much resources the batting can use in the remaining overs. And hence fixes a target based on that.
Hope i successfully confused you more. That's not the intention though. DL method isn't too hard to understand if you get the underlying logic. Maybe we can discuss this in a separate thread and I can explain in better and simpler way. Let's not spoil this thread.