When the cancellation refund of 50% in Tatkal gets applicable, chances of Tatkal WL getting confirmed through system will be there. With 0% refund now nobody cancels tatkal tkt. But tatkal berths are empty in the train. Hence if you have a counter ticket not online irctc, then you can take a chance in tatkal bogey and 99% your tkt will be confirmed by on duty TTE. It has happened many times with me and my colleagues.