My statistics class was a long time ago, but I think the calculation on "dealer wins ties" is 3 / 51 = 5.88% dealer advantage. (Once the player card is determined, there are 3 other cards of the same rank that can tie it, divided by the remaining 51 unknown cards in the deck.)

However, I think the comparison is simply to the 5.00% commission on winning bets in the traditional game. The frequency of these 2 events occurring is different (dealer ties, offset by no winning commissions taken), but this new game will give the house an added advantage.

With no tie outcomes possible, the volitility (or "streakiness" or standard deviation) of the game would increase too, I think. Still, the game may be a popular alternative for players who become impatient with so many no-decision outcomes in the traditional game.