Google Flights explains its reasoning for 'best' flights with the following:
We chose options that give you the best trade-off between price and convenience, based on factors such as duration, number of stops, and airport changes during layovers.
To select these results, Google Flights compared offers from over 300 travel partners, including airlines, online travel agencies, and aggregators. Results may not reflect all available offers.
Google may be compensated by some of these travel partners, but this doesn't affect the ranking of results.
I'm curious about the first and second sentences. How is the "..., based on..." justified in grammatical terms? The second sentence begins with "To select these results, ..." That also seems off.