Plus: players who left teams heading for relegation and won the European Cup in the same season; deliberate own goals; and average teams. Mail us or tweet @TheKnowledge_GU

“Real Madrid made an £8m profit on Cristiano Ronaldo when they sold him to Juventus for £88m. He’s 33! What’s the biggest profit made by a club on a player in their thirties?” wonders George Jones.

Cristiano Ronaldo may have obliterated the transfer record for a player in his 30s but, when it comes to profit, he is not the king. It’s hard to give exact figures because of exchange rates and conflicting reports of some transfer fees – hence the use of ‘around’ approximately 472 times in this answer – but we can safely say that at least two thirtysomethings have earned their former clubs a greater profit than Himself.

Fiorentina made around £20m when they sold Gabriel Batistuta to Roma in 2000. Batistuta moved to Florence from Boca Juniors for around £1.5m in 1991 and was sold for £22m nine years later and at the age of 31.

Who has won the World Cup and European Cup in the same year? | The Knowledge Read more

He was, until recently, both the most expensive and the most profitable thirtysomething. But, as Jozef Brodala points out, Leonardo Bonucci grabbed both crowns last summer when he moved from Juventus to Milan for around £35.2m: they signed him for around £11m, which means a value of £24.2m.

Never mind all these superstars – Rob Fielding has a far more interesting footnote. “If we’re talking percentage profit then I reckon you may struggle to beat Port Vale’s John Rudge’s wheeling and dealing,” says Rob. “In 1988, he purchased a 32-year-old Ron Futcher for £35,000. Futcher was Rudge’s sixth choice but he helped to inspire the Valiants to promotion via the play-offs.

“In the higher division the ageing striker didn’t get as much match time and asked for a transfer. Remarkably Rudge managed to sell the then 34-year-old for £60,000 to Burnley in 1990 – an increase of 71%.

“No wonder Sir Alex Ferguson once said of Rudge – ‘Every game I go to, he’s there with his “bonnet” on, and that’s dedication. Port Vale should go down on their knees and thank the Lord for having him. We all dread a phone call from John with his “I’ve got no money, what’ve you got, I fancy this one” routine. Eventually he gets a cheap player and turns him into a better one.’”

It doesn’t quite beat Fiorentina’s 1,366% profit on Batistuta, but it’s still a pretty good tale.

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Airlifted from bottom to top

“Virgil van Dijk started last season at Southampton, who were close to going down, and ended it with Liverpool who were close to becoming European champions. Has anyone played for a team that have gone down and won the European Cup in the same season?” enquires Mike Coxon.

Thanks to those of you who pointed out two prominent examples of this. The first is Trevor Francis, who started the 1978-79 season with Birmingham, who would be relegated, and finished it by scoring the winning goal in the European Cup final for Nottingham Forest.

Gary Cahill also successfully deserted a sinking ship in 2011-12. He started the season with Bolton and moved to Chelsea in January. Four months later he started in their Champions League victory over Bayern Munich.

Facebook Twitter Pinterest Trevor Francis nods the ball past Malmö goalkeeper Jan Möller to score the winning goal in the 1979 European Cup final. Photograph: Bob Thomas/Getty Images

Noble Francis also has an interesting variation on this theme. “Carlos Alberto de Jesus played for the Fluminense side that finished 19th out of 24 teams in 2003 in the (Campeonato Brasileiro) Série A,” he writes. “Then he moved to José Mourinho’s Porto in January 2004 and won the (Portuguese) Primeira Liga and European Cup by May.” Not bad.

Knowledge archive

In October 2012 we looked at players to have scored deliberate own goals (featuring 149 in one match) in protest against their club, their manager or the referee. And though this email in response doesn’t exactly fit the bill, it’s an enjoyable yarn nevertheless:

“Austria’s greatest football coach ever, Ernst Happel, loved to score own goals during his playing days against his teammate and close friend Walter Zeman,” wrote Jörg Michner. “Both played for Rapid Vienna and the Austrian national team, Happel being a defender and Zeman obviously a goalkeeper. When Rapid were crushing the opposition, as they often did in the 1940s and 50s, Happel used to get bored at the back and occasionally took the ball, scored an own goal and taunted Zeman: “Lucky for you I didn’t hit you in the head or else you’d be dead,” he would shout in broad Viennese at his keeper. When Austria were preparing for the 1954 World Cup against a local selection in Innsbruck, with the score 14-0 to Austria, a bored Happel put the ball into his own net from 20 metres out.”

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Can you help?

“Following the Malcom saga, it got me wondering about other last-minute transfer switches. What are the latest times in a transfer process that a player has backed out of one deal for another?”

“Can any team to be more average than Bristol Rovers?” asks Gerry Prewett. “After the end of last season, the Gas had played a total of 4,030 League games from the time they joined the League in 1920 (including their one season in the Conference). The stats are: W 1,495 D 1,037 L 1,498 GF 5,767 GA 5,760.”

“Cristiano Ronaldo had scored 10 goals against Juventus prior to his move to Turin. Has any other player more frequently inconvenienced their future employer?” wonders Richard Forsythe.

Chris McAlinden (@chrismca88) @TheKnowledge_GU My mate and I were discussing shirt designs and started a list of pro teams who traditionally have a “V” inverted chevron for home strips.



So far we have Velez (Argentina), Bordeaux (France), Melbourne Victory (Australia) and Airdrieonians (Scotland).Any others?