The probability of winning 199 or fewer out of 523 is 8.9696e-8, or about one in ten million.
Wondering if you expected the probability to be higher or lower, considering you said the chances of winning 523coin flips is 49.5%. The chances is almost 50%, but (in reality?) the probability of winning 199 of that seem really low. I assume both words are somewhat synonymous. I sometimes interchange them.