I might be interested in giving it a try, but I'm not sure I understand how the ranking works:
"The winners are the top 20 users that accumulated the most free credits during the month of August playing only the 2 games Live Roulette and Live Baccarat"
=> Is this the total amount of credits you earn, no matter how much you lose, or just your final balance? Do reloads affect your score (say, someone reached a final balance of 500 without ever reloading vs someone reached a final balance of 600 but reloaded twice) ?
It's the total amount of credits on the fun account balance at the cut of date (31st of August 00:00). The 4x200 reload won't be removed from the finale balance. Therefore each participants has 4 "chances" to increase his balance over the initial 200.
The competition being for fun and entertainment purpose a strategy that take high risks with high potential winnings will be rewarded higher.
My strategy would be to try three times bets at maximal exposure in case I bust out I would have one last chance from the finale reload. I would then play it much more conservative.