In-Between side bet

[buccobaseball24]

The casino I visit often just introduced a new side bet called "in between" where you use your first two cards as the "high" and "low" and then the dealer's up card has to come in between for you to win. So if you are dealt K3 then any card 4-q would be a win.

I'm 99% sure the payouts are as follows:
If all 3 cards match it pays 30-1
A one card spread pays 10-1
Two card spread 6-1
Any other spread 1-1

Aces are supposed to be high only. So a2 is your best hand but ak would be one of the worst. However, since the side bet was very new, a lot of the dealers didn't understand it. One appeared to be counting all aces as high OR low and was paying out on hands like aJ when the player got something like a T. Once I realized this I started max betting the prop ($50) every time, but wasn't able to take advantage of the easy money. I hit a few big spreads for even money but then the dealer took his break.

Does the dealer error make this side bet +ev?

 

[Midwestern]

the dealer error reduces the -ev of the sidebet in general, but not in any kind of quantifiable way.
You'd need more precise statistics, like dealer makes payoff error 1 out of 3 times. with this knowledge, you'd add gains + add back the losses you already counted on 2 card combos that included an A other than A2 or AK .