whl, the route is also important if you're crediting your miles to UA Mileage Plus. NH flights trans-pac and intra-Asia (except mainland China) credit at 100%, it's only the domestic, China flights, and Europe/India flights that may credit lower on an S fare. Actually since it's a UA codeshare, I believe it should credit to UA at 100% regardless, you can typically ignore operating carrier if it's a codeshare on the same carrier & mileage program.

If you're crediting on another program then probably you're looking at 50% since as Kacee mentioned *A uses operating carrier to determine.