Originally Posted by
hbtr
no idea how the fare was constructed, but just for laughs I compared the cost of LAX-BOS-ORD to the cost of booking LAX-BOS and BOS-ORD as separate one-way tickets and the cost was almost identical (and way more than LAX-ORD) so my guess is they were two fares combined.
Most likely the LAX-ORD fare had routing rules that did not allow transiting BOS, so you were seeing an end-on-end construction.
If you price it in matrix you can know for sure; they show you which fares are used and which segments they cover.