Originally Posted by
B302LS
Been seeing something weird recently and wondering why. When I search for flights, I often get cases where I get cheaper flights with more search terms. In theory, this shouldn't be the case as more restrictions with more search terms should result in fewer choices.
For example, my most recent search:
Departing: GRR
Outbound routing codes: blank
Outbound extension codes: blank
Outbound date: April 6, 2023
Destination: CPH
Return routing codes: blank
Return extension codes: blank
Return date: April 10, 2023
Cheapest option is a Delta combination of flights for $845.
If I add "alliance skyteam" to both outbound and return extension codes (all other fields the same), I get 49 options that go down to $580. Why is that? I would expect the cheaper itineraries form the narrower search to be the default ones shown on the broader search as they are perfectly reasonable. I have confirmed that they are bookable via bookwithmatrix and Priceline.
The main limitation on how optimal the results will be is Matrix's timeout. We on the outside don't know Matrix's internal structure so we can only guess as to the effect of various limitations we add in the query. Some limitations presumably allow Matrix to narrow the initial set of flight/fare options it considers, while others presumably force it to do more work later in selecting flights. From the results you're getting, it would seem that adding an "alliance" extension code narrows the initial set of flights, allowing Matrix to better search them for the lowest fare. I've found that in some cases, adding specific flights to the extension codes causes Matrix to return "No flights found," even though without those specific flight restrictions, the results will include those flights. I can guess from this that adding specific flight restrictions caused Matrix to do more processing later, during which it timed out before it found results that had those flights.