Math question on 21+3, 4 deck

One casino in Nevada plays the blackjack side bet, 21+3, using 4 decks. The payouts are as described in WOO (i.e., 9 to 1). WOO shows that the 6-deck game has a house edge of 3.23860% and hit rate of 29.17%. So what are the house edge and hit rate for 4-deck, 21+3? How many casinos in this world use 4-deck games and why? Thanks for any reply.

Quote: UCivan

One casino in Nevada plays the blackjack side bet, 21+3, using 4 decks. The payouts are as described in WOO (i.e., 9 to 1). WOO shows that the 6-deck game has a house edge of 3.23860% and hit rate of 29.17%. So what are the house edge and hit rate for 4-deck, 21+3? How many casinos in this world use 4-deck games and why? Thanks for any reply.

The 6 deck version that pays 9 to 1 has a hit rate of 9.68 % (pair with no flush pays -1 to 1)
4 decks house edge: -4.2439198623242 % hit rate : 9.58 %

miplet, Thanks. You're right the hit rate is less than 10.

I can see 4-deck gives the casino a better house edge. Will 2-deck still have a even better house edge for the house? 4-deck blackjack variants / side bets are hardly seen anywhere else.

2 decks house edge: 7.2617844748056% hit rate : 9.27 %
I put a copy of my spreadsheet in google docs