Before we venture into why Arsene Wenger has regressed in the transfer market (next slide), we have to establish his genius and how much influence he wielded.
Wenger at His Best
£25 million—the inflated amount Barcelona forked out for a 27-year-old Marc Overmars  (from BBC Sport).
£21.8 million—the profit Arsene made from Nicolas Anelka in 1999 , who was only a Gunner for two seasons and a half.
£11.5 million—the combined cost of Patrick Vieira, Gilberto Silva, Emmanuel Petit, Alex Song and Mathieu Flamini.
£7 million, free transfer, £150,000 and academy graduate—how Wenger constructed the Invincibles' back line (Lauren, Sol Campbell, Kolo Toure and Ashley Cole) .
Arsene's Calculated Risks
He turned rejects like Vieira (AC Milan) and Cesc Fabregas (Barcelona) into world-class footballers.
Did some left-field scouting by going into Sweden and plucking Freddie Ljungberg from Halmstads.
Ignored a major red flag in Thierry Henry's Serie A failure  and proceeded to not only spend a significant amount in bringing him to Highbury (£11 million; per BBC Sport), but changed the Frenchman into a No. 9.
Signed Robin van Persie—branded uncoachable during his spell with Feyenoord —for £2.75 million.
Blind faith is the phrase to describe Le Professeur waiting eons for RVP to finally put one great season together. He then sold him to Manchester United for £24 million after the Dutchman turned into Judas (from BBC Sport).
Bought Emmanuel Adebayor for £3 million, when he had scored four goals in 21 games for Monaco, and sold him for £25 million (to Manchester City) four seasons later.
 Converted to around €40.6 million for a player that didn't make one single PFA Team of the Year in three Premier League seasons. Wenger sold poor old Joan Gaspart a bill of goods.
 At the time, it was second-most expensive transfer in football history (from AFP via New Straits Times).
 £7.15 million for the Premier League's best defence. Manchester United bought Rio Ferdinand for £30 million (via BBC Sport).
 In an interview with FourFourTwo.com, Thierry claimed his form had nothing to do with his exit from the Bianconeri.
 Here are some brilliant quotes about a young, brash, misunderstood and troubled van Persie (compiled by The Telegraph's Oliver Brown):
Bob van Persie; Robin's dad: "When my wife and I divorced, he came to live with me until he was in his twenties. Until he turned 12, I had a hard time controlling him. But suddenly he turned positive. He found football as something to put his energy into."
Rik van der Donk; sports teacher: "Robin was a rascal. He always made a statement [i.e. Van Persie 2 PSV 0!] when he came into the classroom—teachers had difficulties with him."
Carlo de Leeuw; worked with RVP at Feyenoord: "The coach [Bert van Marwijk] asked him to warm up, but he replied, ‘No, I don’t want to’, or words to that effect. Then he was told to go away. He was that kind of player. You had to keep him short, you know what I mean?"
Martijn Krabbendam; football writer: "Van Hooijdonk [One of the world's most prolific forwards at the time] was not the type to be overruled, and I watched Robin push him away, thinking ‘What is he doing?’ He hit the bar with the free-kick, so you could say he was right. It showed character."
Krabbendam added: "He [Van Persie] was essentially a street kid talking to the coach [teammates, staff, media, etc.] like he was one of his friends. He didn’t always have the vocabulary to verbalise his feelings."