Merely knowing the final data is meaningless. Even if you know that your system's win rate is 50%, it is meaningless unless you have experienced the events leading to that outcome in a chronological order. For example, while the result of a coin toss is 50%, there can be a prolonged period where heads only appear 20% of the time. It would be wrong to conclude that "the probability of heads is no longer 50%" just because such a period continued for a while. If you keep tossing the coin, over a large enough sample size, the probability will converge to the true rate. This is the law of large numbers.

What matters is not just knowing the final performance but how much of the process leading there you have experienced and understood chronologically.