Each time i fly redeye from LAX - FLL or FLL - LAX it seems that my flight is always a codeshare with Korean Air/KLM/Air France etc...

With my Silver status, i always end up around 20th in line for a status upgrade.

I do pretty well on upgrades when it's not a codeshare. Is there any way to determine which flights will have codeshares or not before i buy the ticket?

Delta.com gives some information, but not as much as i'm looking for...

download the Skyteam schedule or subscibe to one of the services

If you don�t get your upgrade, you�re way better of with Korean Air/KLM/Air France. I mostly fly *A Y TATL and try to avoid UA/US/AC whenever possible.

DL does not offer elites of KE/KL/AF upgrades. This does not affect your upgrade chances. Redeyes are notoriously difficult to upgrade on.

I'm curious as to why you think that the relevant factor in your upgrade success is codeshare flights. You state that every time you fly LAX-FLL it's a codeshare and you are low on the upgrade list. So are the flights that you are taking where you do get upgraded the same route? the same time? the same day of the week? etc. etc.

There are many factors that affect upgrade percentage on flights, some of which might be related to codeshare or not, but to me it doesn't seem to be the case.

Despite my skepticism about your reasoning, I do have a pretty good answer for you.

The best to avoid codeshare flights is to use any of the flight schedule resources from SkyTeam or any flight schedule resource that will show you multiple airlines. You can go to skyteam.com and find the Find Flights link to do a search online. I have an application on my Treo 755 that is a Palm OS app for the SkyTeam timetable. These timetables will generally show all SkyTeam flights between the cities you choose, when you see flights from multiple airlines for the same times, you know you are looking at a codeshare.

Thanks for the answers so far,

Most codeshare flights I'm on seem to be populated by more people willing to pay for first class, so there's less room for an upgrade. I could be wrong though.

At least on nwa.com, it clearly states on the fare search screen "operated by X".

Flight numbers are another way. Non-NW flights are usually 800+.

Suprised you can't apply the same logic to DL.

There is always the option of "not flying Delta."

Or fly Delta more to get higher status.

+1 Often biz travelers can justify a FC or upgradeable Y fare when a red-eye is involved.

It's not that the OP is unaware of a codeshare carrier. You missed the point. He is flying on DL metal and he want's to know if other airlines are codesharing on that DL flight. Looking for "operated by X" is not going to help him. He knows who the operator is. He wants to know who ELSE is selling tickets.

I think the OP is right here. When a flight is a codeshare with (foreign) carriers, there are likely more passengers on an international itinerary on the flight than on non-codeshare flights. Since many businesses allow employees traveling more than x hours to fly in business, and these codeshare flights have more pax flying on long trips, you're more likely to have people on paid J tickets than you'd see on a standard domestic flight.