Originally Posted by
mother-
(With the caveat that I'm really only thinking about domestic flights and not all the crazy extra fees and complexity for Intl)
I think that once again you're not talking about broken fares but fares from origin to destination, and that type of fare (married segments if connecting) is exactly the logic that would be in step 1 of what I outlined, and is what Delta.com already does.
And
The linked article notes a case where there was a massive last minute fare sale on flights to London from the East Coast that allowed open jaw returns to major US cities. E.g., NYC-LHR-BOS was allowed. In this scenario, it would be very possible that a flight NYC-LHR-BOS (qualifying as RT with OJ) is cheaper than a last minute OW fare NYC-BOS or even NYC-BOS. The algorithm above would not find this because the cheaper fare is filed as a RT fare NYC-LHR, but the algorithm only looks for:
1. NYC-BOS fares
2. Fares to other airports that are lower (just NYC-LHR is an expensive OW fare and not cheaper)
(Btw, I know you excluded international fares. I used LHR just because it is referenced in the article. The same facts could apply domestically as well. There aren't as many cases in practice since most RT are just 2xOW domestically these days. But, that hasn't always been the case. And there's nothing stopping an occasional violation of this norm.)