They key to a succesful bump is your ability to charm the gate agent. Smile a lot. Flirt if your gender is appropriate. Crack jokes if inappropriate. Forge a bond. Make up a story about how your office booked you on an earlier flight than needed so you don't mind being bumped. In fact, that would allow you to watch the game in the lounge/bar. Maybe your old college roommate lives in this town and you wanted to get in touch with but didn't have the time.... Be creative but believable. The agent will remember you as the guy with the story versus all the other anonymous folks.
Always try to ensure that the agent TAKES your boarding pass from you. With the boarding pass out of your possesion, the onus is upon them to ensure you get it back in time to board the flight. I benefitted once when the agent simply forgot about me and a colleague and sent a flight out with 2 open seats while bumping us! It also ensures that your name will be top of the pile at decision time when push comes to bump.
Be assertive enough that they know they don't have to explain the drill to you, but not so pushy that they feel you are gaming the system. As the flight begins to close, stick around the fringe of their vision but don't approach them until they signal you to or until they are idle.
At the end of the day, always wait until everyone else has gotten their compensation and then ask for $100 more than they got, with a wink and an "I won't tell". By that stage the agent is on a high after having dealt with a stressful situation and you stand a pretty good chance of actually getting it.
If your reroute is acceptable but not optimal take it anyway. Don't piss off the primary agent. Just walk to another gate/counter/desk and tell another agent that you "just realised" that this other itinerary was available and would they be so kind as to make the change. It works more often than it doesn't!
Bumping is an art form. In time you will learn it. It took me 5 years to fine tune my technique but at the peak I was able to rebate almost 40% of my total travel spending through bumps. Alas, my flying is mainly international (hence less flexible) nowadays, so the numbers are down, but the technique is timelesss!
