The concourses are silent when, deep in the Emirates Stadium’s bowels, Chief Inspector Pete Dearden’s briefing begins. Arsenal’s 4.30pm kick-off against Chelsea is still hours away but the fixture carries significance as a London derby and because the Premier League champions are hosting a realistic challenger. Dearden is a senior officer in the Metropolitan police’s public order command and Sunday’s matchday commander. He is, to borrow football jargon, giving the pre-match team talk, running through intelligence and in-game tactics. “Set the right style and tone,” he says. After Dearden has finished, the police room becomes a pseudo-station for the afternoon, with all incidents triaged by the same crime officer. Football offences can be found in niche legislation, and the Met wants London’s matchdays to be, so far as possible, policed uniformly. Matchday is the iceberg’s tip. The Met’s 17 dedicated football officers (DFOs) each work full-time on one club, planning each fixture with the matchday commander. All 500-plus games the Met covers per season are risk-graded using factors such as risk level of supporters, proximity, recent history and kick‑off time. Dearden labels Sunday’s game “medium medium”. “Our mantra is safety, security and service,” Dearden says. “We appreciate that with 60,000 people in the stadium not everybody is going to behave, but we want to reduce the overall risk of the likelihood of disorder.” Three police support units (PSUs), each containing an inspector, three sergeants and about 21 constables, have been assigned to the match. In addition, there are the senior team and 20 operational football officers, or “spotters”, on duty. Clubs also have their own in-house safety teams, with, in effect, both parties doing their homework before collaborating. Arsenal’s operation involves about 1,000 stewards and response team members. They are the first responders to any incidents within Arsenal’s footprint. When