Speaking last week, before another standout win as Tottenham's stand-in boss, Cristian Stellini explained the difference between a coach and a manager.
A coach, Stellini said, thinks only about improving players and creating a positive environment in training, while a manager has to worry about making big decisions and ultimately "feel the responsibility" for every aspect of the team.
Stellini is primarily a coach, but he is also proving an astute manager in the absence of Antonio Conte, albeit with constant guidance from the latter, who is expected to return to work this week after a period of recuperating from gallbladder surgery in Italy.
Yesterday's 2-0 victory over Chelsea — sealed by second-half goals from Oliver Skipp and Harry Kane — maintained Stellini's 100 per cent record from four matches this season and ensured he has overseen three of Tottenham's best League wins over the campaign since Conte fell ill at the start of the month.
As Stellini's reputation as a manager-in-waiting grows, so too does the pressure on Graham Potter, whose last three top-flight wins with Chelsea span four months.
The terms 'head coach' and 'manager' are more or less synonymous in English football today, but there is little doubt as to which category best suits Potter.
Potter is, above all, a fine coach, having climbed from semi-professional football in Sweden to one of the top jobs in Europe by virtue of his excellence on the training ground, improving players and instilling clubs with his philosophy.
Plainly, he would not have come this far without being emotionally intelligent and a good manager of people, but the 47-year-old does not, it is fair to say, share many of the key characteristics of an old-school 'manager', who is often more about creating an atmosphere for his players to shine than tactical nous.
For all his qualities, Potter is no force of personality, whose charisma alone makes up part of his control over the dressing room and club.
The problem for Potter is that this expensively-assembled and bloated Chelsea squad currently feels more in need of managing than coaching. In time, Chelsea co-owner Todd Boehly believes Potter will be a success, and he may be right, but in the immediate term the club feels more in need of a leader than a tactician — at least until the new signings are bedded in and unwanted players have been moved on.
More than a project coach with clearly-defined ideas, Chelsea would benefit from a ruthless decision-maker, willing to adapt their system to suit the best players and create a relaxed atmosphere around the club. A Carlo Ancelotti type, for example.
Potter, though, is not used to managing an oversized group of overpriced egos, and his decision-making is increasingly muddled, as he attempts to keep everyone happy. At Spurs, he made six changes from the defeat at Southampton but his side were just as lifeless. Of the two players hooked at half-time against Saints, Kalidou Koulibaly kept his place in the team at centre-half but striker David Datro Fofana did not even make the squad.
Hakim Ziyech — who had a red card for a shove on Emerson Royal rescinded by referee Stuart Atwell at the end of the first half — continues to start games despite having been an administrative error away from joining Paris Saint-Germain in January, while Pierre-Emerick Aubameyang was back on the bench, but overlooked for midfielders Mason Mount and Denis Zakaria when Chelsea needed a goal.
As Aubameyang was finally waiting to be introduced, Kane scored Spurs' second to kill off Chelsea.
By contrast, being led by a coach rather than their manager may be exactly what Spurs needed and Stellini afterward compared the players to teenagers who had been forced to mature in Conte's absence. Without a figurehead to hide behind, the players have taken on more responsibility, while also seeming to benefit from Stellini's mellower presence.
The introduction of Richarlison to the side in the last two matches has helped to raise the intensity, while the terrier-like Skipp, who opened the scoring with a rasping strike from 20 yards, has added bite and hunger to the midfield.
Their blip at Leicester aside (when Conte was back in the dugout), Spurs have won four of their last five League games, keeping clean sheets in all their victories, and they appear more resilient defensively and better able to cope with pressure points than they did a month ago.
Conte will be under pressure to maintain their turnaround when he returns to work, particularly as Stellini let slip last week that his "dream" is to one day be a manager in his own right.
For Potter, the job is more like a nightmare.