You can think of it this way. Flipping a coin, is that a deterministic process? After all, knowing all parameters, could you not define which side it land on? The question there is 'how to know'. In reality it becomes non linear, a chaotic system that depends on subtle differences in initial parameters, this assuming a same environment, of the throw. On a macroscopic plane this is the world we live in. On a microscopic plane you have statistics, giving you probabilities of a outcome. You have certain rules defining what you can know of, etc but there is no guarantee for a outcome, more than the statistics preceding it.