I have been following LHR-TYO and TYO-LHR for the past few weeks to look for J/F award availability within the next 3 months. I found BA and JAL availability open up fairly consistently in both directions at any point <T-7, and around T-14. However I was surprised to find from time to time, an entire inventory on BA sometimes opens up (4 J and/or 2 F) - I've seen this happen twice around T-60 and around T-80.

Can anyone explain the logic (if any!) behind this? Simply as innocent as an FTer cancelling bookings for his/her entire entourage, or something more sinister??

Thanks!