you need to bet 32768 times in a row and you will have it for sure...
[...]
In fact no. You could bet a billion time and sill not get it, it's possible. And you could bet one time and get it. That is the beauty of probabilities, leading to the interesting concept of "luck".
Just for your reference:
Chance to hit x3000 with 1 bet = 1/32768= 0.00305%
Chance to hit x3000 at least once with 100 bets = 1-(1-1/32768)^100 = 0.3047%
Chance to hit x3000 at least once with 10000 bets = 1-(1-1/32768)^10000 = 26.3%
Chance to hit x3000 at least once with 1000000 bets = 1-(1-1/32768)^1000000 = 99.9999999999944%