The classic Monty Hall problem: https://en.wikipedia.org/wiki/Monty_Hall_problem
Results:
100000000 samples were examined where each sample represents one "Monty Hall cycle"
+-------+----------+-----------+
| | Switched | Kept |
+-------+----------+-----------+
| Wrong | 16661354 | 33339726 |
| Right | 33330483 | 16668437 |
+-------+----------+-----------+