Take your sure thing, let's pretend this week it's Green Bay -9 against the Niners for 25 bucks, which pays 22.73.
Then, you take that game and take the 49ers at +9, and another 2 teams in a parley.
If Green Bay covers, you get paid. Your parley fails, however, it doesn't matter because you lost zero money as one win covers the parlay loss.
However, if Green Bay doesn't cover, then your parlay is already 1/3rd complete, and you have a good shot at turning that 22.72 into almost 150 bucks, or 6-1. Thoughts?