Fine, then don’t use it. It’s running a Monte Carlo simulation, which is the only reasonable way of doing it.
From the repository for all human knowledge:
Monte Carlo methods (or Monte Carlo experiments) are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in simulating physical and mathematical systems. Because of their reliance on repeated computation of random or pseudo-random numbers, these methods are most suited to calculation by a computer and tend to be used when it is unfeasible or impossible to compute an exact result with a deterministic algorithm.
If a 5% uncertainty is not good enough for you then just run more iterations as Calvin said, or, get crackin’ on that super computer.
A percentage chance of winning/losing/drawing, coupled with the average IPC loss, should be sufficient information for any reasonable player to make a decision. It’s certainly better than no statistical information at all and I don’t want to play with anybody that needs more information.