It was an advertisement for the Premier League that could have been scripted in Richard Scudamore’s office. Velvet-plaited football, goals, a late twist: Liverpool’s see-sawing thriller against Spurs pretty much had it all. But what really stood out was the sheer number of young players. Eleven of the 22 starters were under 24, the most of any Premier League game this season. Meanwhile the average starting age was 24 years 175 days, the lowest since Manchester United beat Arsenal 8-2 in 2011.

No wonder there were giddy dispatches suggesting that a “new generation” of English footballers, personified by Jordon Ibe and Harry Kane, were bursting through. Some even claimed that Roy Hodgson could start to dream of a “new dawn” for English football.

New dawn? More like a false one. I say this with confidence because of research by Simon Gleave, the head of analysis at Infostrada Sports, who has tracked the changing numbers of young players (aged 23 and under), peak players (24-29) and veterans (30 and over) in the top flight of English football since the 1970s.

What he found was fascinating. In the early 70s and 80s, between 35% and 37% of starting appearances in the old Division One were made by footballers who, being under 24, would qualify for the PFA’s young player of the year award. By 1991-92, on the eve of the Premier League era, it had slipped to 27%.

But despite the FA’s Blueprint for Football promising in 1991 that the Premier League would emphasise developing English talent, those numbers have continued to slide. In 2011-2012 just 21% of top-flight starters were 23 or younger. This season it is 17.4% – the lowest in the modern era.

Top flight starting appearances. Illustration: Infostrada

To put it simply: in the 70s and 80s around four players in the starting XI would be 23 or under. These days the average is fewer than two. Instead clubs are playing more peak-age performers at the expense of youth.

Does this matter? Yes, for two reasons. It suggests that the resources that clubs have thrown at their academies have not brought more young players through – which has obvious knock-on effects for the England team.

Gleave illustrates his point by looking at Manchester City, who opened their £200m training facility in December. In 2007-08 they had seven players under 24 playing regularly in their first team. A year later it was six. During this period they blooded many young players, including Joe Hart, Vincent Kompany and Pablo Zabaleta who are still regulars.

However, as Gleave points out, “in the last two and a half seasons only two players under the age of 24 have played at least a third of league games in a season – Matija Nastasic, who is now at Schalke, and Eliaquim Mangala, who is usually blamed when things go wrong”.

This season, 95% of Manchester City’s starting appearances have been made by peak age or veteran players. Only Stoke (96%) are worse at giving youth a chance.

Manchester City and Premier League age curves. Illustration: Infostrada

In the short term this is not necessarily a problem. But having the oldest squad in the Premier League, as City now do, is a ticking time bomb. Veteran players eventually need to be replaced. And in the age of Financial Fair Play, City cannot flash Sheikh Mansour’s credit card quite as flippantly as they once did.

Gleave has also investigated how the pool of young English talent has slowly evaporated. Again, his results are striking. In 1994-95, there were 70 players aged 23 or under who started at least a third of Premier League games – 51 of them English, with a further 12 from the rest of the British Isles or Ireland.

A decade on, in 2004-05, that figure had dropped to 62 – with only 36 of these young players English. This season, there have been 50 players under 24 playing at least a third of matches in the Premier League – and just 25 of them are English.

Premier League talent decline. Illustration: Infostrada

So in 20 years the number of young Englishmen playing fairly regularly in the top flight has halved. So much for the frothy talk of a new generation.

There are still opportunities in other European leagues. As Gleave points out, 123 players aged under 24 are playing regularly in the Eredivisie this season – 83 of them Dutch. Yet how many English players under 24 are fine-tuning their trade in the Bundesliga, La Liga, Serie A, Ligue 1, Eredivisie or Primeira Liga? Just one. Josh McEachran, who has started three Eredivisie matches at Vitesse. Sadly the time-honoured reluctance of most English players to go abroad remains – unless it is somewhere with a pool in the summer.

When Gleave crunched more numbers, he found that few players make their top-flight debut after their 23rd birthday. Instinctively that makes sense. The window for young stars to get games and opportunities to develop at the elite level is not a wide one. It soon slams shut.

Of course, there is another side to this: for a Premier League manager, facing the pernicious pressure that comes with being permanently three defeats from a crisis, it is easier to trust in experience than to roll the dice on youth. But as Liverpool and Spurs have shown, youngsters given time and patience can succeed. Just don’t necessarily expect others to follow their lead.

For more information and examples of Simon Gleave’s work in the area of ageing in football click here.