Theoretical Seating is the name of a module in FLY which allows BA to allocate seating by status. FLY being BA's new global dispatch control system used at airports to allocate, check-in and reconcile passengers and bags to flights. This thread gives background to this topic, a worked example and some references. By all means comment or post questions about your own experiences.

I need to thank BLHD in particular, DrGee, irishmanlev, Scottiebhoy, Bat 21, gustavmahler, aidy, TheMajor and V10 for their help and assistance with this thread.

The best description I've seen of theoretical seating was in this post by Reality_Czech. In summary, from 72 hours before departure seating options will be restricted to enable better seating arrangements for high value customers. This is defined as Gold and Silver (plus oneworld Emerald and Sapphire) passengers, however on fuller services it is the Gold passengers who benefit significantly more than Silvers. On less full flights Silvers will also get some favourable treatment.

Now this is a big difference from before: in the past certain rows were kept for Goldcardholders, such as front row CE, front row(s) on Domestic, but at T-72 an active Silver could often find a better seat further forward on the aircraft. The pre-72 hour situation persists, and Silvers will see good seat options to that point, towards but not necessarily at the front of the cabin; But at T-72 there won't necessarily be any improvement options, and on fuller services, while Golds will get some good choices, Silver cardholders may not get access to these forward seats. See the next post for a worked example.

Implications in summary:
- If Gold, even if you book late you should get a good seat.
- If Gold there's a much higher chance of getting a blocked/empty seat next to you
- If Silver you best ensure you have a good seat before T-72. you can't assume you can improve on it after 72 hours. On the other hand you will get more seat options then than Blue or Bronze cardholders
- If Silver and in company then Theoretical Seating does open up adjoining seats if necessary
- If Silver and single, after T-72 while the seats on offer may be further back, it is possible that the passenger will have an empty seat next to them on less full flights.
- Silver cardholders face two downsides: not just losing the ability to get front row seats at T-72 in some cases, but also sometimes not being offered exit row seats which could be offered to Bronze passengers.
- If using ExpertFlyer, there is an option in My Account / My Account to enter your BAEC number. This will then show more accurately the seat options open to you. See the the worked example for details below.
- Bronze doesn't seem to get the benefit of seat blocking but may give access to good seats, sometimes better than Silver (exit rows) and better seating than Blue.
- Unsurprisingly, improvements to status passengers must have a disadvantage somewhere, and to Blue / no status passengers, who will find it much more difficult to get an empty seat next to them. However the back of an aircraft is probably still the place to find that.
- Be very careful not to split your travel companion on to a separate booking if their BAEC/oneworld status is different to your own: you may find it nearly impossible to get seats next to each other. Golds/Emeralds can ring up BA to get seats together under the TCP provision, a somewhat clunky and manual process. But otherwise if on 2 PNRs and one passenger has no status, you may well want to pay for a seat early on, if you want to sit together.