Yeah it paid 2*bet, now it pays 1.5*bet, while an ordinary win rewards 2*bet. Draws return the bet to the player.
no you got it wrong again.
IF YOU DONT RETURN BET:
blackjack pays: 2.5*bet
ordinary win pays: 2*bet
IF YOU RETURN BET (which is what you should use in your calculations):
blackjack pays 1.5*bet + bet or 3:2
ordinary win pays bet + bet or 2:1
please learn about blackjack before implementing a blackjack casino...