It is really difficult to tell for KA flights. They are unpredictable:
* There are many flights with availability wide open, then suddenly everything is done the night before depature.
* Many passengers do not have assigned seats, but there are also a few flights with a lot of seats assigned.
* There are many flights with few passengers doing OLCI.
* There are also flights that I have BN# above 200 even if I check in 3 hours before departure.
You cannot use seat maps to predict availability.