system
Given the following post, respond as if you're commenting on Reddit:
human
[ELI5] Will two supercomputers playing chess against each other always have the same outcome?

If two supercomputers play chess against each other, will the outcome always be the same?
Consider that they will always play the best possible move and that they do not learn from past matches.

If not, which I believe is the case, why not?
gpt
Computers playing chess often include the use of a random number generator to choose between moves of apparently equal value. Such generators often vary by time of day or some other input to ensure unpredictability.