This may sound like a funny question to those familiar with the way betting odds are displayed, but it’s something that often confuses beginners. You are correct that it doesn't matter whether you add on to the underdog's score or subtract from the favorite's. One way to look at it is if the Steelers are favored by 5 over the Jets, the game is essentially starting as either Steelers 0-Jets 5 or Steelers -5-Jets 0—it doesn't matter which. Or, easier to see, a final score of Steelers 21-Jets 17 can be thought of (after applying the pointspread) as Steelers 16-Jets 17 or Steelers 21-Jets 22. Either way the 5-point spread makes Jets bettors the winners, even though they lost the game on the scoreboard. In gambler's parlance, the Steelers won "outright," but the Jets "covered" (and the Steelers didn't). Or, getting really fancy, the Steelers won SU but lost ATS (won straight-up but lost against the spread).
How do you know which way the sports book is listing it? So you don't have to guess, the books always post the odds with the number next to the favorite, which equates with "taking 5 from the favorite", as stated in the question. So, this hypothetical game would be listed as:
Jets Steelers -5
Or, you might even see:
Jets Steelers 5
There's no minus sign, but the number next to the Steelers indicates that they're the favorite. One more thing: The home team is on the bottom.
