In order to calculate pilot's ranking the following parameters are used:
1. Average points* number scored per sortie = AS = score/sorties
2. Return to airfield ratio = RR = landings_at_airfield/sorties
3. Sorties when pilot survived ratio = SR = 1-(deaths/sorties)
4. Flight time coefficient = K = 1-(1/flight_hours)^1.2 (see chart)
Final formula for the ranking is the following:Ranking = AS*RR*SR*K
*For Air Ranking points granted for air kills are used, and for Ground Ranking - points for ground kills.