Plus: namesake clubs and scorers and the biggest difference in points between top and bottom. Mail us your questions and answers or tweet @TheKnowledge_GU

“We all know Neymar’s transfer to PSG was the most expensive ever, but what is the highest numerical figure paid for a player?” asks Will Hughes. “Neymar’s transfer converted into Zimbabwean dollars doesn’t count. The transfer must have been paid for in that currency, and its value at the time.”

We begin our number-crunching quest in Vietnam, where Julian Unkel suggests Datsakorn Thonglao’s move from Hoang Anh Gia Lai’s to Muangthong United for 3.7bn Vietnamese dollars – around $200,000. Wez Hunter can quickly trump that, with a 12bn fee for Phuoc Tu, who moved from Thanh Hoa to Xuan Thanh.

Next up, Chris Charlton-Matthews takes us to Iran, where Andranik Teymourian joined Esteghlal FC from Qatari club Al-Kharitiyat for a cool 32.9bn rials (around £2m). Chris then realises he should have headed straight to pre-Euro Italy, where Nicola Ventola joined Inter from Bari for 40.6bn lira.

Which player has moved most in his career without a transfer fee paid? Read more

Staying in Serie A, there are a whole host of contenders from pre-Y2K. Chris Sloley nominates Christian Vieri (Lazio to Inter, 80bn lira), while Tom Aldous confuses matters by suggesting Hernán Crespo, who moved from Parma to Lazio for 35bn lira cash, in a deal worth 110bn – Matthias Almeyda and Sergio Conceicão went the other way.

Even after the Euro was introduced in 1999, lira was still legal tender in Italy until 2002, so Brian Connell can raise the bar with Gigi Buffon’s move to Juventus for 100bn lira, and Jörg Michner can vault over it with Zinedine Zidane’s switch from Juve to Real Madrid costing 150bn lira.

So, can anyone knock Zidane off the top spot? Step forward former Bolton goal machine Mario Jardel. Here’s Sean DeLoughry: “In the summer of 2000, the Turkish lira was worth 625,000 to the dollar. Galatasaray met Porto’s $28m buyout clause for Jardel, setting them back 17.5tn Turkish lira. When Jardel moved back to Portugal and Sporting a year later for $30m, the lira had slipped to around 1.4m to the dollar, and Gala banked around 42tn Turkish lira for the sale.

Can anyone beat that? Email knowledge@theguardian.com or tweet @TheKnowledge_GU

Namesake clubs and scorers

“Earlier this month, Cammy Keith scored both goals for Keith FC in their 3-2 defeat by Rothes. What other instances are there of a goalscorer with the same name as their team?” muses Chris W.

This is not a first for Scottish football, as Dave Claes points out that current Dumbarton player Andy Stirling has scored for both East Stirlingshire and Stirling Albion. Andy spent the 2011-12 and 2012-13 seasons scoring nine goals across 57 games for East Stirlingshire. Mr Stirling then had a spell in 2014-15 when parent club Dunfermline Athletic loaned him to Stirling Albion, where he netted twice in 10 appearances.

Dave also brings an international flavour to the knowledge, by adding that on a more well known scale, Stephen Ireland netted four goals in six matches for the Republic.

Facebook Twitter Pinterest Stephen Ireland, left, celebrates after scoring for the Republic of Ireland against Wales in 2007. Photograph: Ross Kinnaird/Getty Images

It may still be a rarity in Britain but the Americas is a hotbed of namesake scoring action. Tom Dockery has brought to light a number of players to used their name and feet to great effect. Aided by the fact many clubs there are named after legendary figures, Tom got to work to find Peru’s Club Juan Aurich S A, which has understandably had several goalscorers named Juan, including Juan Orbegozo and Juan Seminario, who earlier earned the Pichichi with Barcelona.

Are there any footballers with identical names at the same club? | The Knowledge Read more

Over in Bolivia, Jorge Becerra scored his only professional goal for Bolivia’s Club Deportivo Jorge Wilstermann in 2008. There are no shortage of Juans and Jorges but surnames are more rare for namesake goals. In 2017, however, Blas Díaz scored nine goals with Club General Díaz of Paraguay’s Primera Divisíon. Marcus Joseph could not find a team which shared his surname so instead had to accept netting nine goals for the abbreviated Joe Public FC in Trinidad and Tobago.

Tom adds: “I imagine that the most recent occurrence of a goal scorer who shares a name with his club occurred on 27 February 2018 when defender Luis Ramírez scored one of Atlético San Luis’s goals in their 2-1 victory over Pachuca in Mexico’s Copa MX.”

To wrap up, we have a couple of examples of players scoring against teams with whom they share the same name. Liam Evans reminds us that Bobby Charlton scored on his debut for Manchester United on 6 October 1956 against Charlton Athletic. He got a hat-trick in the return at The Valley the following February. And Lindsay Davis points out that Deon Burton, while playing for Scunthorpe, scored at Burton in a 2-2 draw.

Knowledge archive

“What is the greatest difference in points between the champion and the last-place finisher in the top English division at the end of a season?” wondered David Shepherd back in 2005.

At the time, the answer came from the 1984-85 season, where champions Everton amassed 90 points from 42 games and Stoke City came last with a paltry 17 – a gap of 73 points. The Premier League has taken inequality to new heights, with two seasons since then surpassing the record – and in 38-game seasons, to boot.

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In 2005-06, Chelsea finished top with 91 points, with Sunderland bottom with 15; two years later, Manchester United topped the table with 87 points, while Derby famously notched only 11 points. The gap on both occasions was 76 points, with United taking it on goal difference – theirs was 127 better than poor old Derby.

On two occasions, a mere 16 points separated the top and bottom positions in England’s top flight. In the 1937-38 season, Arsenal were crowned champions with 52 points, while West Brom finished bottom with 36 points. Ten years earlier, champions Everton gained 53 points, while Middlesbrough propped up the division with 37.

Can you help?

“Why were Nike footballs used intermittently during the 2005-06 Champions League (and seasons preceding perhaps)? In some games, such as Real Madrid against Arsenal in the last 16 and Sparta Prague against Arsenal in the group stage, a red Nike Total 90 Aerow I was used instead of the classic Adidas Champions League ball; it’s always bothered me and I’ve never been able to find an answer” – Oscar Bell.

“Has anyone ever scored a hat-trick with three consecutive touches?” asks Danny Israel. “If not what is the fewest used by a player?”

“I work in university admissions and noticed that the International University of Monaco is based in the principality’s Stade Louis II. I was wondering if any other football stadiums (or clubs) have hosted or even run universities (excluding allowing universities to use their pitches),” asks Ruairí Cullen.

Kameel Gopal (@KameelG) Gambian top-flight club Steve Biko FC is named after the late South African anti-apartheid activist Steve Biko. Are there any other clubs named after political figures of another country?