There's these few live places I know that offer 1x2 basketball lines that are sometimes stale. These are often (significantly) +ev, however I'm not sure of an accurate method for handicapping them correctly due to the unusual nature of 1x2 in basketball (you would lose if it ends in a tie at the end of regulation, i.e. going into overtime). So far I'm just taking vig free pinny closing and subtracting 3% from the moneyline's probability (didn't data crunch anything just my guesstimate from slight research) to get an estimate.

I'm assuming this is a heavily flawed since I'm sure a -2 spread game is not the same as a -12 spread game, and there should be (highly?) different % from NBA to euro league, where these are primarily offered.

Anyway, I was wondering if there is a more accurate method I could use to properly estimate these %'s? I would assume going over past seasons and grouping similar spread games then averaging, or something along those lines would be best, but the limits for these are pretty insignificant, and I don't usually bet any basketball or know where to get bulk historical data (particularly for euro league).