Manchester United were not supposed to beat Manchester City the last time these two shared a pitch. Ruben Amorim was on the phone with his in-laws over paternity, Ruud van Nistelrooy took the reins on short notice, and it was Michael Carrick, not either of them, who somehow walked out of the fixture with the result that stuck in Manchester City's throat for months. That kind of scoreline does not get forgotten by the club that lost it. It gets circled on a calendar.
Now the rematch is here, and it carries the weight of a team looking to settle something. Grudge matches do strange things to how sides approach games: some tighten up and play for control, others come out swinging to make a statement early. Manchester City have the greater incentive to make this one loud. Manchester United have the greater incentive to make sure it isn't.
That tension is exactly what a total goals number is built for. The line sits at 2.5, and the derby's storyline pulls in both directions at once. Does the grudge produce goals, or does it produce nerves? Over or under 2.5 in the Manchester derby is your call to make.