Manchester City will go into this year’s Premier League season as champions but it is their bitter rivals across town that is the undisputed most valuable sports team in the world in spite of spiralling debt.

Forbes top 50 most valuable sports teams places United top of the pile with an estimated value of £1.43bn, up from £1.2bn. This is £250m more than second-placed Real Madrid.

That United is the most bankable brand in sport is no surprise. The club has an unrivalled global fan base of 659 million, enjoy unrivalled success of 20 titles in the most popular football league, Premier League, and has been aggressively building its base in football hungry Asia.

Although United has worrying debts of £424m, the club has huge pulling power when it comes to sponsorship. American Insurance firm Aon pays £19.8m to stick its logo on United’s shirt, DHL Express recently signed a four-year deal worth £40m to sponsor the club’s training kit and Nike contributes £25m a year towards team merchandise sales.

But what does being in Forbes’ most valuable list actually mean?

Very little, if you consider who else figures.

Football clubs, which undoubtedly enjoy the greatest world-wide appeal of any team sport, have seven top 50 entrants, including four in the top 10 – Manchester United, Real Madrid, Barcelona (£838m – 8th) and Arsenal (£825m – 10th).

Remarkably, NFL clubs dominate the top 50 with 32 teams!

According to Forbes, global household names St Louis Rams, Minnesota Vikings and Cincinnati Bengals (all NFL) are all more valuable than Champions League winners Chelsea.

How Forbes works out the rich list is beyond me but I can imagine a lot of it is based on gate receipts, sponsorship and other commercial revenues pouring into a club.

In the mega-rich NFL, which dwarfs football in terms of the stupid amounts of money invested in the game, you could understand such a good showing from grid iron teams.

But in my books, a club’s value has as much to do with its global appeal and fan base as it does with revenue generation, and a complete list would factor this into account.

NFL teams that few people outside of the United States have heard may be valuable at home, but I doubt cashed up investors from the Middle East, Europe or elsewhere would place such a high value on their brand.

The other sports to feature include Major League Baseball (seven entrants), Formula One (Ferrari and McLaren) and Basketball (Los Angeles Lakers and New York Knicks).

The numbers: the world's top 10 most valuable teams:

1 Manchester United - £1.43bn

2 Real Madrid - £1.20bn

3= NY Yankees - £1.18bn

3= Dallas Cowboys - £1.18bn

5 Washington Redskins - £1bn

6= LA Dodgers - £895m

6= NE Patriots - £895m

8 Barcelona - £838m

9 New York Giants - £831m

10 Arsenal - £825m