Same Penetration
Many players discuss penetration in terms of Percentage Dealt. They would look at these game as 50% game and a 75% game.
This is not a good way to think about. It is better to think in terms of the number of unseen cards. Here, they are both 1 deck, which is the same. Given that, the DD would be slightly better mathematically. By that I mean, for the exact same spread, the DD would yield more.
I punched some numbers into BJRM. It doesn�t have 4 decks, but it has 6,which illustrates the point. I compared the two games, first with a 1-8 Wonging, and then with a 1-10 play all. These ar for playing 1 spot only. Here are the SCOREs
Wong (1-8)
DD :64.64
6D: 63.04
Play All (1-10)
DD: 38.69
6D 29.92
If Heat were not an issue. Then the DD would be slightly superior.
Of course, in the real world, Heat is an issue. There is usually more of it at DD. and so players usually can spread less there than in other games. Panama Rick�s posts compares the games for more realistic spreads, and it shows the shoe game was superior. But again, this is because we are forced a weaker spread in the DD game.