Every Leicester player has a book that was given to him by its author, Brendan Rodgers. It is a kind of manual, a general explanation of the manager’s tactical ideas and a section on player behaviour. It is not an overly intricate tome and the players are not compelled to read it. But practically all have done so or at least referred to it.

Most, though long accustomed to being coached, have never been given a similar document. Several have said they were impressed by the time and thought put into it and also liked the unashamed ambition of a manager who declared from the outset how he believed he could get the best out of players and how he expected them to strive to do likewise. “You can’t climb the mountain in a suit,” is a Rodgers line, a catchy way of reminding young players they will have to sweat to get to the top. His book has two merits: it is of practical use for players learning a new way of playing; and it carries symbolic power in a club with big aims.

Last season Leicester finished 46 points behind Manchester City; but they will stand above Pep Guardiola’s side this Christmas no matter how Saturday’s showdown at the Etihad pans out. That extraordinary change is partly down to a slight dwindling at Manchester City but the chief cause is the improvement at Leicester under Rodgers. Which is attributable to a change of practices and communication.

Mocking of Rodgers for supposed David Brentisms will always find an audience but at Leicester his communication skills have complemented his technical knowhow, helping to raise standards and morale. Communication was not a forte of Rodgers’ predecessor, Claude Puel, who did much good work but was at times too cold, at others too imprecise.

To develop the team Puel had to phase out older players who had served the club well, but the way he went about that caused unnecessary ill-will. Puel’s eagerness to advance to a post-Jamie Vardy era seems particularly ludicrous in the light of the striker’s renewed lethality under Rodgers; but the treatment of the long-serving midfielder Andy King, who said he had little meaningful dialogue with Puel before eventually leaving the club in February 2018, also caused resentment.

Rodgers, too, has inherited members of the 2016 title-winning squad whom he will have to move on but he has chosen to treat them as assets for as long as they are at the club rather than alienate them. Wes Morgan and Christian Fuchs were even awarded new contracts shortly after Rodgers’ arrival and continue to make valuable contributions from the bench as well as sharing their experience of staying around the top of the league.

Rodgers’ most significant communication triumph, however, has been the clarity of his training and how it translates into matches. Under Puel too many players felt there was a discrepancy between how they practised and how they were expected to perform at the weekend. Vardy memorably complained that the team felt they were preparing for a marathon but were then expected to compete in a 100m dash, and that is why they often fell short.

Now Leicester are able to play with exceptional intensity because that is how they train. According to the midfielder Hamza Choudhury, “the intensity has gone through the roof”. James Maddison has explained that is not simply a question of fitness, it is also about concentration and choreographed deployment. “I think the word ‘intensity’ confuses people,” he said a couple of months into Rodgers’ reign. “They think it just means running around 100mph but it’s not. We’ve worked on pressing a lot and that is intense by nature and there are a lot of tactical elements involved. We’re constantly learning.”

Even though Leicester tend to have more possession than their opponents, no team have won more tackles than them in the Premier League this season. The individual members of Leicester’s defence are excellent and Wilfried Ndidi is a magnificent screener in midfield, but the team’s well-synchronised dynamism is the main reason they have conceded fewer goals than anyone else. Rodgers’ message and method are understood and applied.

Last season Leicester had a revealing bad habit: they and Watford had the joint-worst record for goals conceded in the first 15 minutes, exposing a measure of muddle in preparations. Watford have not solved their problem – they have the worst record for conceding early goals again – but for Leicester it is no longer an issue (though the biggest test comes on Saturday, as Manchester City have scored more early goals than anyone else).

But Leicester’s biggest improvement has been in their attacking. It seems incredible now that Watford scored more goals than them last season, and even Crystal Palace managed as many. Now Leicester go forward. Leicester’s discipline and tenacity are attacking qualities. Now Leicester penetrate much more often because they have become more knowing. They are not simply more energetic but also more patient.

The message that Puel never quite seemed to be able to get through is that being patient does not mean being slow. Leicester pass and move with great speed but have learned to wait for the right moment to go for the kill.

They have had similar amounts of possession in matches this season as last but have completed an average of 22% more passes per match because they are constantly trying to pull opponents out of shape.

It takes admirable clarity of thought, as well as talent, to upset the established order.