It’s September 2014. A tallish, gangly and occasionally awkward looking boy wearing the number 13 shirt collects possession, fakes inside before shifting back onto his preferred right foot, and scampers off into the space behind the full-back. His cross is headed well wide by a team-mate.

The match peters out into a goalless draw, and few of the hardy souls in attendance, let alone the player himself, would likely have been able to predict that Kylian Mbappé would have two league titles, a handful of domestic trophies, numerous individual honours and a World Cup winners’ medal to his name less than four years later.

It’s not as if he was an unknown quantity. His name was known in development circles long before he got his first youth age-group call-ups for France. He had trials at some of Europe’s biggest clubs. He was a talent. On that September afternoon four years ago though, he was merely one of a number of hopefuls with a dream of making it big, and he didn’t even make the cut for Les Bleus’ 2015 Under-17 European Championship squad. Odsonne Edouard, Maxime Pelican, Jonathan Ikone and Jordan Rambaud were picked ahead of him as Jean-Claude Giuntini, the team’s manager, thought him inconsistent and questioned his mentality.

A year later he was an Under-19 European Champion who had begun to establish himself in Monaco’s first team but, even then, he was on the losing side against Aidy Boothroyd’s England in Heidenheim, where Chelsea’s Dominic Solanke, Izzy Brown, Fikayo Tomori and Tammy Abraham all played. Their respective trajectories ever since couldn’t have been more different, but why?

By way of simple comparison, Callum Hudson-Odoi’s star had been just as bright in his relatively tender years. He too had set tongues wagging as a 14 year-old hopeful at Cobham, and he was an Under-17 World Champion as a 16 year-old playing alongside Jadon Sancho (before taking centre-stage alongside Phil Foden when Sancho left at the conclusion of the group stage) as England triumphed in India. A first-team debut followed less than three months later at the age of 17 years and 82 days; only 100 days older than Mbappé was when he first stepped out for Monaco’s first-team at home to Caen in 2015.

How does a Hudson-Odoi become an Mbappé? How does a world-class youth player become a world-class player?

We know how Chelsea think it happens. Deeply wedded to the loan process, they want their hopefuls to prove themselves at increasingly challenging levels over several seasons before fighting for inclusion in the first-team squad at Stamford Bridge. Thibaut Courtois, Andreas Christensen and Ruben Loftus-Cheek are supposedly testament to that process working. If they stumble along the way, they’re deemed to be short of the required standard, that they never had that potential all along. What would they do if a young loanee excelled in the French top-flight though?

They’ve dipped their toes in the Ligue 1 waters over the years; Matt Miazga’s spell at Nantes looks set to come to a premature end next month, Mario Pašalić was perfectly respectable at Monaco without pulling up any trees but often played ahead of a young Tiémoué Bakayoko, and Jeremie Boga grew up when spending a year at Rennes in the same team as Ousmane Dembéle. None of them were truly great but, had they been, you get the impression they’d have been asked to prove themselves in Germany, Spain or at another Premier League club before Chelsea took a serious look.

Mbappé didn’t do that, and he obviously didn’t need to, adjusting for his lack of experience outside of France by making just about everyone he came up against in the Champions League look like amateurs. That came in his first full season as a first-teamer in 2016-17, a year after he broke through with one goal in 14 appearances but just two starts in the league. He found Vagner Love, Guido Carillo and Lacina Traore in his way up front, and future Wolves pair Ivan Cavaliero and Helder Costa in the attacking midfield position he would supplant them in. Good players that few will ever have mistaken for superstars, and an unremarkable start given what was to follow.

The perfect mix of a burgeoning talent and a club both willing and needing to use him yielded more spectacular results than anyone at Monaco could have imagined in their wildest dreams. A slow-burn approach in which he steadily grew more and more acclimatised to his new surroundings saw him score six goals before the winter break and follow that up with an astounding 18 in the new year. He had arrived.

Some Chelsea fans like to tell anyone who’ll listen that Chelsea are not Monaco, they’re not Dortmund, they’re bigger than that. To a certain extent they’re right, but these are teams that have competed for, and won, domestic titles against rivals with financial might they cannot hope to match. That sounds familiar. They’re also both Champions League teams this season, which is more than can be said for Chelsea, and although Monaco are battling relegation it comes at the end of a cycle in which their best players have been pillaged by Europe’s biggest and best. And Chelsea, who somehow identified Bakayoko as the must-have player from the 16-17 vintage.

While appreciating that neither Monaco nor Dortmund are routinely in a six-way fight for four seats at the big boys’ table, it’s hardly as if they go into each new season hoping for the best and taking a chance on youth development as a low-risk, high-reward venture. It’s a way of life for them, a means of survival, and it continues to yield success. Certainly, each have experienced seasons of catastrophic collapse in recent memory, but then so have Chelsea. For every recent league title, they’ve had a cataclysmic implosion immediately after, and that’s no way to run a football club.

Throughout it all, though, Dortmund and Monaco and clubs of their ilk have been able to develop and produce high-class players the likes of which Chelsea are considering paying big bucks for. What lessons can the Blues learn to save themselves from dropping £70m on Christian Pulisic and turning Hudson-Odoi into that player? The biggest is surely that you ultimately have to develop these players yourself. The very best players in the world, in any given period, have developed outside of the loan system. Relying on someone else to do your work introduces numerous variables that all come with a fundamental loss of control. At their best they only work to a point that still leaves question marks about their (re)integration after returning from a loan, and at their worst they can leave the player questioning his future in the game, as several former members of the Loan Army have painfully testified.

Doing it yourself comes with greater short-term risk but surely longer-term reward. Mbappé’s first ten starts for Monaco were against Evian, Bordeaux, Nantes, PSG, Guingamp, Montpellier, Saint-Etienne, Lorient, Rennes and Bastia. A nice and balanced spread of challenges for him, never exposed in a rotated team full of youngsters, and over the course of nine months. Could Chelsea achieve that with Hudson-Odoi? Their Europa League schedule has been even kinder to them than expected, two of their three League Cup dates this season have been at home where they were favourites to win, and there have been appropriate league matches where he could have been used. He has made just two starts.

You cannot expect Hudson-Odoi to follow Mbappé’s timeline. It’s unfair and impossible; he turned 18 a little over a month ago, by which point Mbappé was just about to explode into worldwide acclaim. Given their respective careers up until their birthday coming of age, though, you also can’t say that Callum doesn’t have something about him that marks him out as special. At every turn against his teenage contemporaries, *he* was the one stealing the show. When you have that sort of player inside your own building already, you have to capitalise on it and do everything to maximise the rewards; anything else is negligent.

Does he have the right mentality? We can’t know for sure until we try. Mbappé clearly did, but his Under-17 national coach demonstrated that even future Balon d’Or winners have their doubters as teenagers, and it’s only when you’re given the chance to sink or swim that you get to demonstrate what you’ve got. It’s the biggest wildcard and the most determinant factor in whether a youngster sinks or swims in the adult game, and you can either take a leap of faith in hoping to discover the answer, or take a risk-averse approach and put your faith in the players who’ve proven themselves already.

Chelsea’s entire process so far has yielded nothing. It hasn’t worked. It’s produced numerous impressive professionals, top-flight footballers, international players, but nothing for the first team. Courtois was a buy-to-loan acquisition who never set foot in the academy and, while Christensen did, he was a sought-after signing by just about everyone in Europe who would have gotten there one way or another. He spent the necessary three seasons inside the academy to qualify as home-grown before getting out and doing his thing at Gladbach, but could arguably have gone earlier were it not for those rules.

Everyone else? Nothing. Debuts have been handed out, some have even flirted with a long-term stay, but bright light after bright light has burned out or illuminated another stadium, another club. Nathaniel Chalobah. Gael Kakuta. Josh McEachran. Jeffrey Bruma. Patrick van Aanholt. Nathan Aké. Lewis Baker. Solanke. The list goes on, usually met with an exclaimed cliché that none of them have set the world alight or pulled up trees since leaving, conveniently ignoring the fact that development is not a pre-determined journey and playing at Chelsea is not the same as playing at Wigan or Brentford or Milton Keynes or wherever else they’re sent on loan to grow, stagnate, or play down to the standard of.

It ignores that some of them, especially McEachran, looked more than good enough when given playing time alongside the legendary core of the team built by Jose Mourinho in the mid-2000s. It ignores that, even when they’ve flashed their credentials out on loan, Chelsea’s safety-first approach commands one more deal which more often than not kills any momentum developed and leaves the player further away from a breakthrough than they ever were.

After Chalobah had torn up the Championship as a 17 year-old at Watford, Mourinho said “We are thinking of letting (him) go on loan for a last season. That is our intention and he knows. For sure he is a Chelsea player. He could be in our squad already but we think one more season will help and then he will come back.” That move was to Nottingham Forest, a club that had finished below Watford the season before, and managed by Billy Davies, who adopted a long-ball and tough love approach that completely destroyed Chalobah’s confidence. He cut that stay short in January, and didn’t play for Chelsea until September 2016, more than three years after Mourinho’s comments.

Abraham had the most prolific goalscoring season by a teenager in the English second tier for more than thirty years, but “a one-season loan in the Premier League, with the promise of starting regularly, is seen as perfect preparation” for his eventual integration into the first team. The club chose Swansea, who turned in some historically low attacking numbers and were ultimately relegated. Abraham, despite making his England debut during that season in South Wales, is now back in the Championhip at Aston Villa no closer than he was when scoring for fun at Bristol City. It’s almost as if the club are sabotaging their best hopefuls, and it’s concerning to read this week that they play to do the same with Reece James, a player many neutral observers are convinced is already good enough for the big time.

If it was easy everyone would do it, and the best have consistently done it themselves. There are no definitive answers, there is no rule book for how to produce a world-class talent, but there are best practices. Maybe the best lessons are there to be learned from the one Chelsea did produce themselves. John Terry did go on loan to Nottingham Forest in 2000, and has always spoken of it as an important step in his journey to the first team, but he was there for just six matches over the course of one month. He had already played eight games for the Blues, and returned before the end of the campaign to feature again.

When Pep Guardiola fielded an entirely academy-developed team while at Barcelona, he remarked that “the player who has come through La Masia has something different from the rest, it’s a plus that only comes from having competed in a Barcelona shirt from the time you were a child”. Maybe the most successful advocate of producing your own talent in the last 30 years, Sir Alex Ferguson, was reminded during a 2015 interview with the BBC that former Liverpool defender Alan Hansen had once told him ‘you win nothing with kids’. His response? “You can’t win anything without them”.

There’s no substitute for your own hard work. The sooner Chelsea come to that realisation the better.