Liverpool just about kept pace with Manchester City at the top of the Premier League table thanks to a calamitous error from Hugo Lloris in the final few minutes at Anfield on Sunday. It was by no means the most convincing performance, although the quality of their full-backs has rightly made headlines.

Elsewhere Cardiff City were unlucky not to take points from Chelsea after deploying a bizarre man-to-man marking system, and Everton finally looked like a coherent Marco Silva side – if only because West Ham United were so hopeless at the London Stadium.

Here are three things we learnt from the weekend action:

1) Robertson & TAA flourish thanks to Poch's early tactical error

Liverpool's 2-1 victory over Tottenham Hotspur has been defined by the work of Trent Alexander-Arnold and Andrew Robertson, the full-backs whose creativity and fearlessness have kept Liverpool going even when the midfield looks stodgy and Mohamed Salah is trying too hard to get on the score sheet. On Sunday, their success was partially the result of Mauricio Pochettino's first-half tactical error; his 3-5-2 formation afforded too much space to the wide men.

Sadio Mane's and Salah's positioning on the outside of the Spurs back three pinned the wing-backs, creating a flat back five and therefore leaving just three in midfield. This meant huge gaps opened in the wide areas for Robertson and Alexander-Arnold, who dominated the first 45. Liverpool could have gone into the break 3-0 up.

Pochettino's switch to a 4-2-3-1 solidified the wings and allowed Spurs to grow into the game, but ultimately it was an exchange between the Liverpool full-backs that led directly to the winning goal in injury time.

2) Cardiff's full-pitch man-to-man marking was a novel way to limit Chelsea

Everyone knows the best way to stifle Chelsea is to man-mark Jorginho out of the game, but most of their opponents this season have then held a rigid defensive shape in their own half. Neil Warnock decided to do something a little maverick on Sunday, deploying a man-to-man tracking system for every position on the pitch.

The three midfielders picked up one Chelsea midfielder each and diligently followed them around, while full-backs Lee Peltier and Joe Bennett tracked Pedro and Willian so tightly they spent long portions of the game in central midfield. Even centre-back Bruno Ecuele Manga followed Gonzalo Higuain when the Argentine dropped a good 15 yards out from the Cardiff defensive line.

The plan mostly worked, although ultimately the single-mindedness of the strategy led to Cardiff's downfall. They struggled to adapt when substitutions came onto the pitch, with the more erratic movement of Ruben Loftus-Cheek and Eden Hazard proving difficult to tail. Without a basic structure to fall back on, Cardiff's midfield collapsed and Chelsea grabbed the goals they needed to keep Maurizio Sarri clinging on – for now.

3) Pellegrini's 4-4-2 allow Everton to finally take the form of a Silva side

For the first time in months Everton played with the tactical philosophy of a Marco Silva side, their attacking football mimicking what we saw in Silva's best moments at Watford and Hull City. Their collective pressing stopped West Ham from counter-attacking and ensured forceful possession was maintained throughout; their midfield played one-touch football to suck their opponent into central areas; and their full-backs made lung-busting runs to take advantage of the space created out wide.

Idrissa Gueye and Gylfi Sigurdsson were exceptional, while Lucas Digne and Seamus Coleman look ideal for Silva's tactics. He is perhaps only a striker short of a first 11 capable of challenging the top six, if only Everton can begin playing this way consistently.

But they were helped enormously by Manuel Pellegrini's flat 4-4-2 formation. Given that Marko Arnautovic and Lucas Perez don't work hard enough they were never going to relieve pressure by holding up the ball, while a two-man central midfield is easy to overwhelm. The match became more even in the second half after Pellegrini switched to a 4-2-3-1, but by then the damage had been done.

Best of the weekend – Tactical variations bring watershed moment for Arsenal

There is no one thing that Unai Emery has changed at Arsenal, no easy description to explain how they have accrued the same number of points as 2017/18 with seven games to spare, have risen above Tottenham into third for the first time since April 2017, or have won ten home games in a row. In fact, it is precisely because Arsenal are so hard to read that they are in this position.

Emery's tactical variations were once again important on Monday night. He began the game in a 3-4-2-1, their narrow inside forwards a surprise choice given how compact Newcastle tend to be in central midfield. It worked, however, and when Newcastle upped the tempo in the second half (by sitting 15 yards higher) Emery's change to a 3-5-2 ensured the tide did not turn. It was a one-two between Alexandre Lacazette and substitute Pierre-Emerick Aubameyang that led to the second goal.

Worst of the weekend – Fulham's possession football

It simply doesn't make any sense to play out from the back – to prioritise short-passing football at all times – when playing the best high-pressing team in the world, Manchester City. But this isn't just about choosing your opponent. Previous possession-centric teams in the Premier League, most notably Swansea City, knew when to begin their short passing; play longer balls and feel your way into a game, and only when the territorial battle is even begin the tiki-taka.

By contrast, Fulham deploy short-passing football no matter the scenario or minute of the match, which is extraordinarily naïve and dogmatic. It is, perhaps, the main reason why they are set to be relegated in midweek.