The only time that this myth would come up is when you are dealt a natural blackjack or a 20 and the dealer has an Ace showing. In fact, the only time you are offered insurance in blackjack is when the dealer has an Ace showing.
The belief on this blackjack myth might sound reasonable, but it is in fact not practical. Here are the reasons these myth-believing blackjack players will insure their blackjacks and 20s:
– If you insure your blackjack you will get an even money payout no matter what even if the dealer has a blackjack.
– If you insure your 20 and the dealer does have blackjack you will wind up with the equivalent of an even money payout because you will lose that round