What is the route? What is your fare class? Days of week? People could probably opine on the chances. For example if you said "IAH-NRT" or "EWR-NRT" I would say "if you have an L fare you have a chance...if you have a Q fare you're dreaming."

If you're just looking at the seat map and don't know what he meant by F9...
do a new search for tickets on the same route. Click on FARE CLASS on the right of the screen for the ticket that is your flight. You'll see how many tickets are still available in each fare class.
To use miles or an upgrade instrument instantly, you need to see some R fares (or RN if you are elite...can't remember if Silver is high enough to use RN...)

Often they'll release some first class seats to R fare and then process upgrades by miles. This is better for them than just giving it to us cranky 1ks, you're paying something of value. When they do this depends on the route. For example EWR-IAH or EWR-SFO...hahaha. They often won't process any upgrades on these route until day before, and you probably have competition.