Can anybody work out the house edge and best strategy for this blackjack variant?

6 decks, continuously reshuffled, dealer sticks on soft 17.
No doubling.
A win pays £1.04 to the £1* including BJ
A player 6 card hand beats dealer 21 but not dealer BJ

Splits:
If you split your stake does not increase, your stake stays the same but now it rides on both hands having the same outcome; If both split hands win than the hand is considered a win, if both split hands lose it is considered a loss, if one wins and the other loses or either pushes it is a push. You can take more cards on split aces. Only one split.

*Average amount based on a minigame it qualifies you for but for all intents and purposes assume it just pays out a flat £1.04 per hand.

First, these rules suck deep and wide - the house edge will be large when judged by conventional BJ games.

No doubling and virtually no payoff for blackjack eliminates two important components of the player's advantage. The player will rarely have a 6 card non-busted hand (<0.5% of the time) and quite frequently would have won the 6-card hand anyway.

Does the dealer peek at the facedown card when the face-up card is an Ace? I assume not from your description.

Whoever does this calculation will need to develop a new set of basic strategy rules, especially for:
- splitting high pairs. I think you will always split 77 and 88 but what about 99?
- splitting low pairs (22 unsplit is a good start towards an unbusted 6-card hand)
- hitting a 5-card 17
- hitting multicard stiff hands (12-16)

That's a lot of work for an unattractive variant.

Whomever does this, please state what short-cuts you took, i.e., did you use an infinite deck approximation?

Gordon but you get paid more for each win. Does the .04 make up for the doubles and bj. I assume this is an online game.

Quote: GWAE

Gordon but you get paid more for each win. Does the .04 make up for the doubles and bj. I assume this is an online game.

Yes, you are correct!! That will reduce the house edge. So, its a more interesting game to analyze than I first thought.

Quote: GWAE

Gordon but you get paid more for each win. Does the .04 make up for the doubles and bj. I assume this is an online game.

Eh, I'm on the side of this looks like a bad deal (could be wrong just an educated guess). From traditional blackjack, having BJ pay even money is -2.27%... no doubling is another -1.48%, 6 card charlie is worth +0.16%...

So before calculating what the extra 4% in payout does, you're already fighting an uphill battle of about -3.59% to traditional rules. Add to this it's on a CSM, thus no counting.

He's also right that this will be a lot of extra work to completely revisit the splits and to calculate what the 4% extra is worth. Mike might do it because it's clearly a "real" game someone has seen somewhere and he often is searching for new variants to compute, but I'm not sure how many other people will burn the man hours over this when the educated guess would presume it's not very helpful.

Extra 4%
Talking out loud... Getting pulled to something else for work, but also slightly stuck just for a moment... There's got to be a way to calculate (while ignoring the splitting factor) how much the extra 4% payout is worth...

So let's take a generic house edge of .5%.. Now blackjack pays even money, so -2.27% more... Then no doubling -1.48% more. 6 card charlie +0.16%... so the final house edge off the top we're looking at THUS FAR is 4.09%.

So let's play 1,000,000 hands flat betting $1.... Your win rate (number of hands), playing perfect basic strategy is 42%, with a 49% losing rate, and a 9% push rate. So you should expect to win 420,000 out of 1,000,000 hands. Of these 420,000 hands you should get an extra 4 cents on your $1 win.

EV(no extra) = 420,000(1) + 490,000(-1) + 90,000(0) = 420,000 - 490,000 = -70,000
EV(extra 4%) = 420,000(1.04) + 490,000(-1) + 90,000(0) = 436,800 - 490,000 = -53,200

So for your $1,000,000 in action you'll get back an extra $16,800... which is 1.68%. Very good chance I'm looking at this wrong, just the first thoughts to come across my mind. Thoughts?

Well, I've worked out the split rules - they were actually fairly easy to figure out..

Always split (vs any dealer card) : AA, 99, 88, 77, 66, 33, and 22.
Never split: TT, 55, 44

Also:
STAND on S18 vs 2-7 since you cannot double.
HIT all other hands which you would normally DOUBLE.

HIT vs STAND on 16 vs. 10 is even closer than usual because of the 1.04 payout for winning because - player wins more frequently when Standing (vs. HIT) on a 16. However, you should still HIT a 2-card 16 vs. 10 (someone should check me on this.)