In a perfect world where card counters are ignored and one could play with unlimited bet spreads then yes it appears that's the right play. There are much more variables than sheer numbers. All variances from basic strategy are a tell. Do you want to risk being fingered as card counter on doubling 10 vs. 10? Every blackjack players situation is different. Proximity to playable casinos. Number of playable casinos. Costs associated to get to playable casinos. Heat at casinos, etc.
With my circumstances that's a play, I am not willing to make even with a true plus 4.
Howdy, doubling 10 vs 10 other than the size of your much larger bet is a tell in itself, I do not think it too much out of line. Just gives the appearance of an aggressive bettor. The reason I pass up on doing it is that I play shoes and the risk-averse # is +7 true which that play in that situation does not come too often and I consider it trading a very small edge for a lot of added variance.
10 vs 10 (5/6, S17, DAS)
true count EV gain
The sim was 200mil. But I took the percentage of hands played x 100k hands. It's going to take me 3 years to play 100k hands these days whereas KJ might still be able to do it in one.
In a $50 game, my max bet is $200. Pathetic I know. But this is within casino tolerance. I can spread to two hands.
So, for me, in 3 years I will win 4 more double downs than I lose on 10vs10. The max of $200 doubled leaves $400 on the tables to be won or lost. 4 × $400 is $1600 for that particular play. But it will take me 3 years.