For an opening-game upset of the season, Hull City’s win at home against 20-time champions Manchester United was rather convincing.They were 2-0 up after 38 minutes and managed the game with control and comfort in the second half to see out a statement victory. Not a bad start for the Championship play-off winners up against last season’s third-place side, especially as they have the least ‘valuable’ squad in the Premier League, based on Transfermarkt estimates of their players’ potential transfer values.And while the phrase ‘tactical masterclass’ is thrown around more often than it should be, the game plan that Sergej Jakirovic devised — and his team executed — manifested exactly as planned.Let’s start with the shape. Hull had just 29 per cent possession and set up in a 5-4-1 without the ball. The centre-back trio of Semi Ajayi, John Egan and Nobel Mendy brought aerial prowess and box defending in abundance, forcing Manchester United down the sides.Why the back five? “Because United were coming very high with (left-back) Luke Shaw,” Jakirovic told reporters in his post-match press conference. “Also, they’re trying to overload the midfield. That was our main task, to close these gaps between the lines,” the head coach explained.Hull mainly played a 4-2-3-1 last season, when they finished sixth and 11 points off automatic promotion, though occasionally they switched to a 3-4-3 or 3-5-2 — including for the play-off final win over Middlesbrough at Wembley, which brought them back to England’s top tier for the first time in a decade.Here, they caused United problems because Matheus Cunha became harder to access. As the false nine in their 4-2-3-1, they need him to connect moves and bring the wingers into play. The best moments from Michael Carrick’s side in the first half were deep crosses to wide men Patrick Dorgu and Bryan Mbeumo — with a defensive overload and height advantage, these suited Hull.A key detail, especially in the second half when Marcus Rashford replaced Dorgu at left wing, was how high Hull’s back five stayed. They avoided sinking too deep too early, meaning United could not pin them in, and Rashford’s repeated runs in behind never materialised into a chance because either the pass or his movement was timed wrongly.