Originally Posted by
traveller5
I now actively avoid BA to and from Tokyo, unless it is a code share flight operated by JAL, even via Frankfurt or Helsinki.
BA still get a slice of your fare even when you fly JAL or Finnair to Tokyo thanks to the joint venture agreements in place between the UK and Japan. Crediting those flights elsewhere is just reducing BA's commitment even more in the form of not having to issue NTP/Avios to your BAC.