Originally Posted by thomj001

In my experience I find the best upgrade chances for that flight are on the 7 AM (too early for most people) and the 8:30 PM (but, there's no meal service after 8 :-( and the BE dinner is really quite a nice domestic service).

Here's what I do:

Since ALL BE upgrades on the JFK-->LAX flight occur at the gate, its pretty easy to tell the day before the flight where the openings are.

At booking I choose the flight with the best combination of Fare and Arrival Time to suit my needs. Then, the night before departure I scan for upgrade chances on all flights the next day and SDC into an alternate flight if the one I'm booked on looks doomed.

FWIW, As a PM, I'm 6/6 on my JFK/LAX/JFK BE upgrades, most on sLUT fares, and none on the red-eye or post 8 PM routes.