New Blackjack Side Bet

In UK bookmakers (off track betting shops, found on every high street in the UK) have gaming terminals that offer single zero roulette, bingo, and poker games. They also offer Blackjack with the pocket rockets side bet, which the makers claim is unique.

http://www.barcrestgroup.com/game/?id=376

You place a side bet, min £1 that your first two cards are under 9 in total

9 = Even Money
8 = Even Money
7 = 2-1
6 = 2-1
5 = 4-1
4 = 5-1
3 = 10-1
2 = 40-1 (pocket rockets)

What is the edge?

Assuming me and google docs spread sheets are haing a good day:
1 deck = 8.8989441930618 %
2 decks = 5.8999253174011 %
4 decks = 4.4221479004088 %
6 decks = 3.9327232253277 %
8 decks = 3.6886005560704 %

I am getting about 3%
Edit: oops, didn't see miplet's post. My 3% is for infinite decks.
And I can confirm 1 deck and 8 deck answers (did not check others).

Quote: WizardofEngland

In UK bookmakers (off track betting shops, found on every high street in the UK) have gaming terminals that offer single zero roulette, bingo, and poker games. They also offer Blackjack with the pocket rockets side bet, which the makers claim is unique.

Can you check to see if they also offer the 20+ Blackjack game?

http://www.barcrestgroup.com/game/?id=352

Quote: MathExtremist

Can you check to see if they also offer the 20+ Blackjack game?

http://www.barcrestgroup.com/game/?id=352

yes they do, how good is that?

Quote: WizardofEngland

yes they do, how good is that?

Not saying it's good/bad - just trying to confirm it's in the marketplace. Thanks.

Quote: MathExtremist

Not saying it's good/bad - just trying to confirm it's in the marketplace. Thanks.

oh, was hoping you would say it was a good bet!