If Curry goes over, the Warriors are more likely to go over, so FanDuel will give you a worse price. For example, if you parlay Curry over his point total and the Warriors to go over their team total, both at -110, you won’t get a +260 two-leg parlay payout like a regular two-leg parlay because those bets are correlated. So why is there a distinction? Because prices in an SGP environment behave differently than the same prices outside of it. Again, an SGP+ just combines one SGP with other wagers.
You can also add 76ers -10.5 to that parlay to create an SGP+, and the payout will now be +3000. Say you want to bet Warriors guard Stephen Curry to score 40+ points and Warriors center Kevin Looney to get 10+ rebounds in Warriors vs. An SGP+ simply combines an SGP with something else - so it could be two Same Game Parlays together, or combines a Same Game Parlay with other wagers like a spread or total.