Arsenal found a new attacking connection, Liverpool retreated back into their shell and Tottenham's homegrown Oliver Skipp showed up Chelsea multi-million pound midfield. Here's five lessons we learned from the Premier League weekend...

1) LEICESTER SHAPE ALLOWS TROSSARD-MARTINELLI CONNECTION TO GROW

Although the final score line suggests Arsenal only just did enough to beat Leicester City they were always in control of this match thanks, mostly, to a strange tactical shape from Brendan Rodgers that didn't seem to make much sense. In a 4-2-3-1, Leicester decided to drop deep in order to encourage Arsenal forward and look to counter-attack behind them, but despite the disconnectedness in a front four that lacked pace, the real issue wasn't the attacking side of things.

Kelechi Iheanacho was alone at the top, which meant he was useless in cutting off any passing lanes for the Arsenal centre-backs. The M-shaped second line was just as poor, sitting far too narrow to stop Arsenal from simply passing through Oleksandr Zinchenko and Ben White into the final third while at the same time failing to actually surround Jorginho or Granit Xhaka. Instead of cluttering the centre and cutting off the supply, it was a shape that was passive by nature and allowed the visitors to control things.

The telling moment came with the first goal, and here we should praise Mikel Arteta for resting Eddie Nketiah and giving a chance for Leandro Trossard and Gabriel Martinelli to connect. Combining for the opener, they regularly swapped positions in order to confuse a Leicester defence that was exposed by the rather pointless positioning from the midfield and attacking lines.

2) TEN HAG CHANGES SHOW HIS CALMING INFLUENCE

Manchester United's victory in the EFL Cup final was another example of Erik ten Hag making his team difficult to beat and capable of winning the 'moments', not unlike how Real Madrid have been playing in the Champions League – and, more pertinently, not unlike a Sir Alex Ferguson team. We expected the hard-pressing tactical dynamism of a modern manager from Ten Hag but instead they are calm, ordered, and willing to strike at the right time with individual acts of quality.

Casemiro and Luke Shaw provided those, although the real sign of what Ten Hag stands for was his second-half substitutions. Newcastle United threatened to get back into the game after Alexander Isak came on as a number ten and carried the ball smartly through the lines, only for Ten Hag to quickly shut him down by bringing on Marcel Sabitzer and moving from 4-2-3-1 to 4-5-1, adding clout in central midfield.

Then late in the game he brought on Harry Maguire for Bruno Fernandes and moved to a back five. The Man Utd manager is prepared to be defensive, to prioritise rational decisions over tactical dogma, and in that way he truly represents what Ferguson did at the club. Contrary to popular belief they were not a swashbuckling attack team in the 1990s and 2000s, but rather a highly competent unit that knew how to stay in a contest and when to pounce. Ten Hag's team have the same knack.

3) SKIPP AND ROYAL GIVE SPURS THE URGENCY CHELSEA NEED

This was about as dull a contest as we expected at the outset, considering Antonio Conte's side fail to commit many bodies forward and Chelsea are struggling to create chances under Graham Potter. However, ultimately the difference between the sides was summarised by an outstanding display from the all-tackling, all-running Oliver Skipp and another impressive display from the overlapping Emerson Royal.

Both of these players, in the second half in particular, looked to surge forward in possession, fearlessly playing with urgency and getting into attacking positions whenever possible, providing Tottenham with the edge in a game that threatened to be too sideways to provide any goals. Chelsea were by far the worst offenders, and Potter is to blame for a formation that exacerbated his team's problems.

His 4-2-3-1 saw Ruben Loftus-Cheek sit next to Enzo Fernandez while Joao Felix roamed about in a free role, and consequently Fernandez rarely had a forward pass to make. Unlike most top teams, who use an upside down triangle in midfield (think two eights ahead, but to the side, of a defensive midfielder) Potter flipped this around and had two holding players without a fixed presence in front of them. This meant there were no progressive options and nobody in the half-spaces. No wonder Chelsea kept moving the ball aimlessly from side to side.

4) FOREST'S NARROW FORMATION EXPOSED BY MOYES' TACTICAL SWITCH

Nottingham Forest are poor away from home and have a habit of making a flurry of defensive errors in matches, so it is no surprise that West Ham United found a way to breach them on Saturday. Still, David Moyes deserves praise for tweaking his usual system to find a route to goal around the narrow Forest 4-3-2-1 formation.

Steve Cooper's shape is a very unusual one, and although it has given Forest great energy on the counter-attack (having three attackers so close together makes for quick interchanges) it means they invariably leave space on the flanks – should teams choose to focus their attacks here. That's exactly what Moyes did by switching to a wide 4-3-3 and instructing his players to get the ball out into the flanks as often as possible.

Said Benrahma and Jarrod Bowen had superb games because they could isolate a Forest full-back, while the use of Danny Ings meant there was always somebody to cross the ball to. All four of West Ham's goals were built down the wings and scored via crosses or cut-backs.

5) LIVERPOOL CHOOSE THE WRONG GAME TO BE RESERVED

Jurgen Klopp made an obvious mistake by going all-out in the 5-2 defeat to Real Madrid, deploying a high defensive line and embracing the chaos with hard-pressing football of the sort that had provided Liverpool with important wins against Everton and Newcastle United in their previous two. He should have anticipated that a return to the more conservative, men-behind-the-ball setup deployed through 2023 was needed against Real.

It's even weirder that he reverted to this for the visit to Selhurst Park. Patrick Vieira's team are most effective when able to get stuck in with hard tackling in the central third and tend to crumble when forced into their own third. What's more, their breaks have been significantly less effective this season than last thanks to the loss of Conor Gallagher and Wilfried Zahas's waning form.

Klopp should not have chosen this game to be conservative in his pressing. If only he had reversed the tactical setup for the last two matches Liverpool might be in a commanding position to advance in the Champions League and finish in the top four. Instead, their hopes in both competitions look over.