I said that the chance is small for you to be out of the top 20 because the reward for top 20 are all the same.
I would have said your chance is big to be out if the reward is similar to the VIP slot challenge (the higher multiplier, the bigger reward).
With the fact that the reward are all the same, players wont try hard to get higher multiplier because they get the same reward for higher multiplier.
Well congrats for your additional reward, although the reward is just 1/4 of your profit from your winning bet with 1000+ multiplier.