An "innumerate" response
Pretty easy to figure out.
You can do it by yourself.
That is as long as you do not need a precise answer.
You need to know the frequency of both the dealer and the player having a Blackjack simultaneously.
Rounded off, your chances are 1 in 21 and the dealers chances (in a shoe game) are almost the same.
The probability of the occurrence is the product of the two separate events.
1 in 21 * 21 = 1/ 441 On those occasions you would earn 1.5 units as opposed to ZERO under the hypothetical circumstances.
If my 'back-of-the-envelope' figures are right that would mean that you would earn this extra 1.5 units, on average,
approximately once in 7 hrs. of play, bringing the value to 1.5 / 7 = +.21 units. per hour for the Basic Strategist.
That looks very significant to me.
Naturally, the edge to the Card Counter is radically higher as we will be betting greater sums when the density of Aces and Faces
rises, so that we will experience a TENDENCY to have increased wagers when the Simultaneous blackjack windfall occurs.
Now, which smarty pants Math Geek here wants to furnish a proper answer ?