Diffrence between FEP and BAR in post-treatment of alchemical calculation

[shradheyagupta]

What is the distinction between the 'FEP' and 'BAR' estimation methods used in post-treatment alchemical analysis?
Why are there two different calculation method provided, and which one is more effective in prediction?
Also, which of the two methods, 'FEP' or 'BAR', is equivalent to ParseFEP's BAR provided in VMD?"

[fhh2626]

Generally BAR estimator yield smaller statistical error.