Which is the best way to use the BetOnline promo? It lets you pick any NFL game spread, moneyline or total. At the halftime it allows you to surrender it for a freeplay of half the bet. So, if the bet losses you salvage some value; if the original bet wins it still pays, but the promo is spent.
So, the best bet should be one that is already decided at the halftime. My first idea is picking a low over (say Chi-Car O33), if it is 27+ points at the half you could confidently surrender it. Another idea is a large underdog moneyline, if it is 14+ points down at the half take the promo. And the other idea is picking a huge side, say -14 points; if it is losing straight up at the half time, surrender it.
To know which option is better there are two factors: How often the surrender situation presents at half time and the conversion %. If I only take the surrender when the over already hit at halftime, my conversion rate is 100% but the chance presents seldom. If I take it on the moneyline when the team is losing SU at halftime, it could present way often, but the conversion% may be only 70% or so.
Of course, the original bet is on the under, if it is already lost at the half time (the over hit), then surrender has a 100% conversion.
On any bet, the live odds at the halftime gives the conversion rate. If the line is already over 90% loss, then taking the surrender has a very high conversion chance, so take it.
The other strategy to use it is to take only the bets you like (supposedly +EV), and surrender it when it has a high possibility of losing at halftime.