The tenth round of Premier League matches looked pretty drab on paper, but it turned out to be an important weekend at both ends of the table.
Tottenham Hotspur were the only team in the top six not to record a comfortable win, with confident displays from Chelsea, Liverpool, Arsenal and Manchester City, while Everton's display suggested that the title could go to the wire in an unusually high quality year.
Defeats for Hull City and Sunderland have added weight to the theory that two of the three relegation spots have already been decided, and Manchester United endured another frustrating result in an eventful match that did little to quash concerns over Jose Mourinho's waning superpowers.
Here are three tactical lessons we learnt from the weekend's action.
1) Guardiola shows his superb problem-solving skills by changing Gundogan's role
As we pointed out last week, Ilkay Gundogan looked a little bit lost as a central midfielder in City's new 3-4-2-1 formation. Only somebody as unusually gifted as Pep Guardiola would have thought to fix this problem by giving the German an even more prominent role in the team.
Everyone knew that West Bromwich Albion would sit extremely deep and invite City onto them, and so Guardiola's team sheet – Fernando and Fernandinho played while Kevin de Bruyne was left on the bench – was met with bemusement by many.
De Bruyne looked weary and timid during City's run of winless matches, but leaving him out altogether and replacing him with a defensive midfielder was an extremely bold move.
It paid off instantly. Fielding Gundogan higher up the pitch unshackled him from defensive responsibilities (his poor early season form was largely due to his confusion in a new, fast-paced environment) and allowed him to express himself without fear.
Fernando played at right-back in a 4-2-3-1, but frequently shifted inside to allow Gundogan to push on.
It was his brilliant one-two with Fernandinho that outmanoeuvred the West Brom midfield and allowed Gundogan to slip a pass into Sergio Aguero for the crucial opener.
The German midfielder when on to score twice himself, ending City's winless run and restoring confidence in the squad. Guardiola deserves a lot of the credit.
2) Conte's deep defending gives Chelsea the upper hand in matches against lower-ranking clubs
Chelsea's fourth consecutive clean sheet confirmed that they will be difficult to beat for the rest of the season. One important reason for this is that Conte is happy for lower ranked opponents to have a lot of possession.
Southampton like to play long, diagonal passes towards Charlie Austin in the hope that Nathan Redmond will catch the flick-ons in his free role or Dusan Tadic will pick up a loose ball and instigate the counter-attack.
They were unable to do this on Sunday because Chelsea sat back and forced Claude Puel's team to try and pass through them.
This strategy has worked brilliantly all month; the opposition defenders are given as much time as they want in possession but have few good options in the final third. N'Golo Kante & Nemanja Matic form a formidable wall in front of a flat back three to make passing through the middle unadvisable (Kante's tackling and interception stats are lower this year because nobody wants to confront him, so instead move the ball out wide, whereas Leicester's four-man midfield encouraged others to attack Kante's space).
But attempts to distribute out wide are equally thwarted.
The wing-backs can aggressively press onto the wingers (who come short to help build away from Chelsea's deep-lying block) safe in the knowledge that they are covered behind them by a back three that shifts across.
It is a brilliantly fluid defensive system likely to nullify any mid-table (or lower) side, since most managers will feel nervous controlling possession high up the pitch when Eden Hazard and Pedro are lurking nearby.
3) Mourinho simply cannot keep using Marcus Rashford as a winger when there are so many other options available
Man Utd's 37 shots on goal was a new Premier League record, and so it is largely just bad luck that saw them draw 0-0 with Burnley at Old Trafford.
However, they did not look particularly fluid until Rashford was put up front and Zlatan Ibrahimovic, dropping into a deeper role, got on the ball more frequently.
Mourinho has Henrikh Mkhitaryan, Anthony Martial, and Memphis Depay in his squad.
That's £90 million of world-class wingers that are largely unused in these positions, which is particularly bizarre given that all three have the sort of pace and trickery needed to play classic Mourinho attacking football – and in a style that fits with United's traditions.
It is becoming increasingly difficult to defend Mourinho's decision-making or his interactions with the media; the Portuguese looks like a man already in his third season at Old Trafford.
Best of the week – Alexis Sanchez
The Chilean was unbelievably good again last weekend, simultaneously playing as playmaker and striker in a "false nine" role that really didn't look that false.
Arsene Wenger has found the perfect solution to his striker problem; the Frenchman has never really liked traditional centre-forwards but has not managed to find an attacking midfielder to fill the role – until now.
Sanchez looked an awful lot like Thierry Henry at Sunderland on Saturday.
Worst of the Week – Liverpool's defending
The frantic high-pressing employed by Jurgen Klopp has led many to assume that their defensive record can be blamed on wild end-to-end football. This is not the case.
Pressing so high up the pitch is part of a possession-centric mantra that, in theory, helps them keep the ball as far away from their own goal as possible.
Liverpool are only really conceding goals from set-pieces and individual errors, which sadly won't be fixed until Klopp buys new players.
Dejan Lovren is too error-prone and Joel Matip is too inexperienced in England; Virgil van Dijk should be a top target for Klopp, who rarely had to worry about the minutiae of defensive work whilst working with Neven Subotic and Mats Hummels at Dortmund.
By Alex Keble
