Gambling - How to get best result - challenge...

Since there has been a recent thread on gambling, I wonder if someone can come up with the optimal outcome for this situation.

You have 2 betting accounts with $1000 in each.
One of the betting accounts is offering a $250 free bet, to bet on anything you like, sports, horses, etc.
However, you only get to keep the winnings, and not the original stake of the $250 bet if successful.

What method would you use to get the best return, guaranteed?

Lets assume that the odds given reflect the true chances of the bets you are placing.
Lets say each event has a market adding up to 104%
ie. For a rugby league game, the odds offered are $1.92 (52%) and $1.92 (52%), or $1.70 (59%) and $2.22 (45%), etc.

You can make your own market odds, whatever the event, as long as they add up to 104%.

I don't have an answer to this challenge, but would like to see what the intelligent people on this forum can come up with.

How much money will you take from this situation?
wait - you KEEP the winnings of yuor capital, but the capital is lost...?

you would need to make 101% profit just to stay in the black.

that's more than "double or nothing" - which is considered the psychological maximum.

unless i'm missing something?