It all depends on your interpretation of "14% advantage".
If we take it, as Chris as, that you have a straight 14% points more, then 57% and 43% is correct.
There is, however, an alternative to consider:
Assuming that a draw isn't possible, we'll take a simple example of flipping a coin.
If you're evenly matched, you both have a 50% chance of winning.
If one has a 14% advantage (as in, they win 14% more flips), then the answer is given by:
x + y = 1
and
x = 1.14y
This yields x = 0.533 and y = 0.467
This holds, as x is 14% greater than y.
/
To win 6 games on the trot = 0.533 ^ 6 = 0.0229 = 2.29%
I'm not saying Chris is wrong, it all depends on what is meant by the 14% advantage.