On the first day God created commercial avaition....on the second day He created Y, B, M, H, Q, V, and W coach class seats on United....and on the third day He ran amok!!

I just tried to book a standard award (40,000 miles, no capacity controls, no blackout dates) from Burlington, VT to San Francisco the Sunday after Thanksgiving on United. Finding no seats available, I took a look on the Web. I found zero availability for connecting flights from BTV-IAD-SFO, but plenty of availability for individual segments BTV-IAD and IAD-SFO.

I contacted the UA Premier Award Reservation Center, and pointed this out to a very curious res agent. He scratched his head, went away, and on the fourth day he came back with the revelation that no one on his support staff had the faintest idea what was going on. Curiously, one of the flight segments with "zero availability" had at least 17 empty seats on a 50 seat aircraft. My archaeological dig was rewarded with confirmed standard award seats on my desired flights.

It appears that United's yield managers are waiting for dozens of travellers to wave fistsful of dollars at them for individual flight segments.

This is raw capitalism at work....soon we will be seeing $4 fares on off-peak flights and $40,000 fares for the same seats on peak flights .

This process of restricting low-fare or any seats on connecting flights is increasing at UA, but it is rarer at others, I think. I don't really understand it the reasons for it. With respect to free tickets, I have been told that by a UA agent that she could not "build a connection" by separately booking two available flights. That is ludicrous!

Everyone should be aware that using multi-city options on Travelocity or ITN (or your own TA) will allow you to circumvent this strange phenomenon. If Sabre or Apollo will autoprice the itinerary, it doesn't matter that you booked the segments individually and does not violate any rules.

On American it used to be that there were more cheap seats available with connections than with individual segments. This is rarely the case now. Now you have to book each segment individually if you want the cheap fare. Once an agent tried to tell me that this is somehow improper, and she would do it that way just that one time as an exception.

As for agents who won't build your award itinerary, just reserve one segment, and then call back and add another later.