I booked this award flights

1/31
NW135 ORD->MSP
DL4871 MSP->SLC

2/1
NW1169 SLC->MSP->MDW

I took NW135 as booked but when I got to MSP, there was an earlier NW flight so I went to the counter and ask to standby the flight. No problem, NW was able to take over the Delta ticket. One strange thing though. After being added on the standby list, I saw myself as number 4 on upgrade list with 2 spots left. 2 minutes later, the agent called my name and handed me a first class ticket and announced first class is full. I have no idea how I jump in front of the other 3 people.

This morning, I decided to go to the airport early to see if I can get on the DL direct from SLC to ORD. The lady at the medalian ticketing counter (NW check in is at DL counter at SLC) was not very helpful. She kept on saying Delta doesn't do standby and there is nothing she can do for me. So she printed me the boarding pass for my original itinerary and said that's the best she can do. Geez, thanks. After I gone to securty, I went to the DL direct flight's gate and ask to standby on the flight. The Delta GA was actually helpful and spent like 5 minutes trying but he couldn't take over the NW ticket. He told me to go to NW and get them to release the ticket then he may be able to put me on his flight. But my alternative option (earlier NW flight to MSP) was leaving in 20 minutes so I decided not to risk it and went for the earlier NW flight to MSP. Ugghh...last minute standby on a full plane is no fun. I haven't sat in a non-elite couch seat in 5 years. When I got to MSP, there was yet another earlier flight to MDW leaving in 25 minutes. So I ran as fast as I could from G16 to F4 (not close especially since part of the moving walkway is under renovation) and got there just as they were waiting for the wheelchair assistant person to come to push the last passenger onto the plane. The GA at first gave me a couch ticket. When I got on the plane, there were 7 empty seats in F so I went back to the counter and got me an F seat. I thought upgrade is automatic, again, strange.