The summer transfer window threw up a few surprises and plenty of money was splashed, but which clubs were the smartest and who got the best deals?

Remember Moneyball - the film in which Brad Pitt recruits baseball players for the Oakland A's based on data analytics?

Well, London-based investment company Carteret Analytics think they have found a formula for footballers, and even use their system to advise three Premier League clubs on potential new signings.

According to findings from this summer's moves, Arsenal might have overpaid for Nicolas Pepe, Everton should have got more for Idrissa Gueye and a newly promoted team got the bargain of the window.

How does it work?

Carteret Analytics use their system to advise seven clubs in England's top two tiers as well as 12 leading clubs from Europe and the rest of the world.

The data centres on the 'intrinsic value' of a player - a calculated fee based on performances for the selling club and the projected impact on the buying club, as well as taking into consideration their prime age (usually 26-30).

This is essentially the monetary value of the player's contribution to winning football matches and how influential he is to creating and preventing goal-scoring opportunities.

By assessing the intrinsic value, clubs can determine how much money they want to receive for a player and likewise, how much they are willing to spend on any new players.

Have Arsenal carried out bad business?

Arsenal sold Nigerian international Alex Iwobi cheaply to Everton

Arsenal took centre stage on transfer deadline day - selling forward Alex Iwobi to Everton and bringing in Chelsea centre-back David Luiz and Celtic full-back Kieran Tierney. But how did they end up in the 'bad business' category?

Iwobi's intrinsic value while at Arsenal went up to £46.26m but he was sold for just £27.36m, suggesting the sale was undervalued by almost £19m.

Arsenal signed Ivory Coast winger Nicolas Pepe from Lille for a club record fee of £72m - a whopping £21.77m over his intrinsic value figure.

And they were sold short on teenage defender William Saliba from Saint-Etienne and let go of former captain Laurent Koscielny to Bordeaux for more than £20m under his projected fee.

But Arsenal did bring in cover for Koscielny at good value. Chelsea's Luiz was rated at £34.8m but Unai Emery's team brought him in for just £7.8m - not bad for a Premier League and Champions League winner with years of experience in the English top flight.

*All figures cited by Transfermarkt. Not enough data on Scottish football to determine an accurate intrinsic value for new signing Kieran Tierney.

Was Aaron Wan-Bissaka's transfer a fair one?

Despite losing one of their best young players, Crystal Palace actually had a pretty good transfer window, according to Carteret Analytics' data.

As well as keeping hold of key attacker Wilfried Zaha, Palace bought Swansea striker Jordan Ayew for just £2.5m - a figure well below his intrinsic value.

They also received a good sum for full-back Aaron Wan-Bissaka, though run the risk of his potential exceeding the projected value at Manchester United.

Wan-Bissaka, sold for £49.5m, had an intrinsic value of just £23.32m at Palace. That value is expected to rise to £43m at United but that is still short of the fee they paid for him.

Everton bought well but sold poorly

Moise Kean made his Everton debut against Crystal Palace on Saturday

Everton raised eyebrows with their signing of 19-year-old forward Moise Kean from Italian champions Juventus. And they got a pretty fair deal, paying just £4m over his projected value, as well as fighting off competition from the likes of Borussia Dortmund.

They also did well to bring in Manchester City's Fabian Delph for under £9m. The versatile England international had a value of £54.58m to his selling club.

Midfielder Andre Gomes' permanent move from Barcelona cost just £22.5m too, a much lower fee than his intrinsic value to Everton. And of course, the signing of Arsenal's Iwobi was another good piece of business.

But Everton were not as shrewd when it came to selling. Midfielder Idrissa Gueye's move to Paris St-Germain fell £26m short of his intrinsic value.

Shrewd business from Bournemouth and Wolves

 

Wolves broke their transfer record to sign Raul Jimenez but still got a good deal

The best business took place among clubs outside of the Premier League's top six.

As well as Crystal Palace impressing, last season's FA Cup semi-finalists Wolves were smart when signing loan players on permanent deals.

Mexican striker Raul Jimenez, who scored 15 goals in 37 games last season, was signed from Benfica for a club record £34m - a good deal because his intrinsic value was rated at £43.37m.

They also paid less for Belgian midfielder Leander Dendoncker's value by £16.13m after he joined on a permanent deal from Anderlecht.

Elsewhere, Bournemouth brought in Huddersfield midfielder Philip Billing for £15m - half of his projected value fee - and sold defender Tyrone Mings to Aston Villa for an overpayment of £5m more than his rating.

Norwich bag a bargain, Spurs sell cheap

Tottenham let Kieran Trippier go to Atletico Madrid for just £19.8m

Premier League new boys Norwich City got the steal of the summer.

They bought Sam Byram from West Ham for just £747,000. He was valued at £27.7m by the selling club but is significantly lower for Norwich at £7m. They have still secured a player with Premier League experience for just over 10% of his monetary value though.

And at Leicester, they bagged a good deal for Newcastle's Ayoze Perez. The 26-year-old was sold for £13m less than his intrinsic value for the Foxes.

So who got ripped off? Well, Tottenham sold defender Kieran Trippier to Atletico Madrid at an undervalue of over £40m.

The England international was valued at £61m while at Spurs, a rating which increases for the buying club.

He joined Atletico for just £19.8m and at 28 years old, remains in his peak. Should Spurs have asked for more money?