As Monty Hall pointed out in interviews, he was not obligated to offer the opportunity to switch and sometimes did not. So in this case knowledge of the actual

As Monty Hall pointed out in interviews, he was not obligated to offer the opportunity to switch and sometimes did not. So in this case knowledge of the actual show may have contributed to confusion. https://en.wikipedia.org/wiki/Monty_Hall#Monty_Hall_Problem https://en.wikipedia.org/wiki/Monty_Hall#Monty_Hall_Problem (But vos Savant stated in later columns that most of the critical responses she received assumed that the host was obligated to offer the switch, so they were genuinely confused by the paradox.)