The fewer the flips, the higher the chances that the tally differs from the expected 50%. We notice that the average of observed results converges to the expected value as a larger number of trials is performed. This is called the law of large numbers. Law of Large Number
You can only rely on expected outcomes if you are guaranteed a large number of repetitions. Otherwise, they are misleading (the law of large numbers requires a large number of repetitions). Law of Large Number
The law of large numbers says that, as the number of trials increases, the average outcome converges to the expected one. We saw that this applies to ergodic contexts only. In non-ergodic ones, irreversibility limits the number of trials, thus preventing the law of large numbers from applying. Law of Large Number Ergodicity