#4 The Spurs' midfield conundrum
Despite enjoying a lead with just 45 minutes more to go, Pochettino's men conceded three goals in the second half, which cost them not only a win but also an important fourth place in the league standings.
It was a night when the Spurs really failed to connect as a team. Both their goals came from set pieces which they couldn't add on to later, as they weren't able to gain an advantage from open play. Poor passing and lack of possession aggravated the problem further, as the midfield section involving Dier, Alli, Christian Eriksen and Moussa Sissoko looked starving for inspiration.
The 4-1-2-1-2 formation was ideally meant to utilise the gaps in Arsenal's initial 3-4-3 and thereby help Son and Kane move forward, while Eriksen, Sissoko and Alli kept the supply line well-fed. Up until this, things worked but when Emery made changes in his squad, Pochettinho failed to catch up.
The system which was supposed to take an advantage of the opponents' gaps, started filling with gaps instead, as the players could no longer complete passes or make runs with proper support.