How does united.com choose to list award flights?
Departing in the next few days PRG-SFO trying to get LH first (O class FRA-SFO) and it's available.
I'm trying to go to PRG-FRA the day before so I enter that date and tons of stuff comes up. In fact, 198 options. Now only about 10 or so are option in first.
The one I really want, which shows on Expert Flyer, is this.
Day 1 PRG-FRA 2pm-3:10pm (I class)
Day 2 FRA-SFO 10:35am-12:50pm (O class)
The above flight does not appear on united.com and it prices at 18,000 more miles as it is requiring point to point.

So what I really want to know is why does united.com offer these flights? It would seem more flying, more cost, etc.
And by the way, the Day 1 PRG-FRA still shows I9 which is much more full than the flights it is offering PRG-FRA.
Here are some examples it is offering.
Day 1 PRG-MUC-FRA - all in I
Day 2 FRA-SFO O class
or
Day 1 PRG-WAW-FRA - all in I
Day 2 FRA-SFO O class
or
Day 1 PRG-BRU - all in I
Day 2 BRU-FRA (I) FRA-SFO (O)
or
Day 1 PRG-ATH - (I)
Day 2 ATH-FRA (I) FRA-SFO (O)

In my case, even though PRG-FRA shows available in I, whether looked at PRG-SFO or PRG-FRA in I and then FRA-SFO in O, united.com nor 1K reservations can book it without charging more miles.
Instead of flying 256 miles PRG-FRA it is suggesting PRG-WAW-FRA for 876 miles or PRG-ATH-FRA for 2097 miles.

I find it confusing and odd.