Brentford pioneered a new approach to set-pieces but Arsenal have since perfected it

In Arsenal’s preparations for Wednesday, set-piece coach Nicolas Jover has especially been focusing on how to block Brentford’s most aerially decisive players – namely, Sepp van Berg – from “accessing key zones”. Jover’s much-discussed work isn’t so much about delivery routines, as attempting to co-ordinate what actually happens in the box; the smaller details that define the finer margins.

None of this will be any secret to Brentford, since they essentially came up with…