Originally Posted by angatol

I suspect it's a time limit, i.e. you just get the best option it found in the time allocated to your search. If you really want to find the best option you need to have the most restrictive search. e.g. if I were searching for options from FCO to SEA on oneworld, I'd try FCO::SEA/alliance oneworld, get a fare basis, say, I7SALE, then search FCO::SEA/alliance oneworld;f ..I7SALE. When it offers me LHR, I'd then reject it in the next search with FCO::~LHR/alliance oneworld;f ..I7SALE, etc. etc.