Mathieu Flamini forced to cover huge area as Arsenal centre-backs play deep and other midfielders stay too high up pitchLiverpool required an extremely late equaliser courtesy of Martin Skrtel but Brendan Rodgers’ side had been superior from the opening moments, causing Arsenal considerable tactical problems throughout.Rodgers’ 3-4-3 formation was no surprise considering he had used that system in Liverpool’s previous two matches, against Manchester United and Bournemouth, but Arsenal appeared unprepared for the challenge.