Most blackjack players are unaware that the casino's edge in blackjack is a function of the playing rules.
Some rules are more favorable to the casinos while others favor the player more.
The above affects appear in the excellent book Knock-Out Blackjack by Fuchs and Vancura. They are approximate affects since the above percentages will vary slightly with the number of decks of cards being used. But for our purpose they will do just fine. Since the above percentages are additive, you can use the information in the table to get a rough idea as to what the casino's edge is for a given set of playing rules. For example most casinos in the Midwest offer a 6 deck game where the dealer stands on soft 17 and player's can double down after pair splitting.