Plus: cross-national cousins, bossing the FA Cup without lifting it and the greatest age difference between team-mates. Mail us or tweet @TheKnowledge_GU

“How many defenders have scored a hat-trick from open play?” asks Jack Tanner.

Not that many, is the short answer, if our pretty extensive search is anything to go by, Jack. There are few defenders who have achieved the feat with the aid of a penalty, Denis Irwin, Fernando Hierro and – bizarrely – Gary Gillespie among them. And then we move on to examples of defenders who achieved the feat from open play but not while playing in a defensive position. For some reason we can’t fathom, Steve Staunton, a left-back for most of his career, leapt off the bench to score a second-half hat-trick for Liverpool at Wigan in the League Cup in October 1989, but he replaced Ian Rush in a forward position. No defender has scored a hat-trick in the Premier League, though Steve Watson, converted from a full-back into an attacking midfielder by David Moyes at Everton, did the trick in a 4-0 win over Leeds in 2003 so is about as close as it gets (Irwin’s Manchester United hat-trick came in Europe).

But if we want a perfect example to answer the question, how about goal-plundering centre-back Aden Flint, who scored three goals from open play for Bristol City in an extraordinary 8-2 walloping of beach-bound Walsall on 3 May 2015, as City celebrated winning League One in style. Flint’s goals consisted of a volley, an insouciant back-heel/rabona finish (obviously) and a close-range tap-in. “I said to the strikers at the end of the game that they should be ashamed of themselves when someone like Aden has gone out there and scored three,” cackled manager Steve Cotterill. Flint scored 15 in total for the season. No wonder Middlesbrough forked out £7m for him.

“Former central defender and current conservative politician Alpay Özalan scored three goals from open play for Turkey during 2002 World Cup qualifiers against Macedonia,” writes Önder Susam. “The then-Aston Villa player scored two headers and poked one into the empty net, which was from an offside position. Those were his only goals for Turkey in any official game. I wish he was remembered for this rather than his antics against Portugal in Euro 2000 or his shambolic defending against Switzerland in a 2006 World Cup play-off.”

Here’s Chelsea centre-back Magdalena Eriksson scoring a hat-trick of headers from corners for Sweden against Iran in 2016. One, two, three …

Fotbollskanalen (@fotbollskanal) Varför ändra ett framgångsrecept? Magdalena Erikssons hattrick var exakta kopior av varandra! https://t.co/s7ESkOw4iY

Oh, and Stan van den Buijs scored a hat-trick for Anderlecht in January 1995. The trouble is, he was playing for Germinal Ekeren, the poor chap.

However, Bernd Jatzwauk has unearthed a four-goal gem from the Bundesliga. “Bernard Dietz scored four goals as a defender for MSV Duisburg against Bayern Munich on 5 November 1977.” They came in the 20th, 49th, 75th and 78th minutes in the 6-3 win. “He went on to become the most prolific goalscoring defender in the history of the Bundesliga with 77 goals.” None appear to have been penalties or free-kicks.

‘Me and my cousins, and you and your cousins …’

“I was listening to the BBC’s World Football podcast recently where Pat Nevin shared the surprise news that he and Terry Butcher are cousins,” reports Michael Fryer. “Does anyone know of any other cousins who played for different countries?”

Turns out there are plenty of examples. “Mark Chung and Craig Ziadie are cousins,” writes Dan Ryazansky. “Chung was born in Canada, but played 24 games for the US. Ziadie was born in the US, but played 26 games for Jamaica. Both played for the MetroStars (now New York Red Bulls): Chung between 1999 and 2001, and Ziadie between 2002 and 2004.

Dirk Maas points us in the direction of Mark Viduka (Australia) and Luka Modric (Croatia). Unlikely relations you might think, but they are cousins through the former Leeds striker’s father, Joe, who emigrated from Croatia in the 1960s. Dirk has done his homework, adding that Marcos Assunçao (Brazil) and Marcos Senna (Spain) are cousins, as are Manuel Fernandes (Portugal) and Gelson Fernandes (Switzerland), and Granit Xhaka (Switzerland) and Armando Sadiku (Albania). Former Wales defender Eric Young can name the ‘Guv’nor’ as a cousin, former England and Manchester United midfielder Paul Ince.

Facebook Twitter Pinterest Luka Modric of Croatia and Mark Viduka of Australia don’t share playing styles but they do have family links. Composite: Getty Images

“There is at least one example of brothers playing for different countries,” writes Harry Curtis. “John Hollins (Chelsea, QPR and Arsenal) played one game for England in 1967, while his older, goalkeeper brother Dave Hollins (Brighton and Hove Albion, Newcastle United and Mansfield Town) played 11 games for Wales.” Pete Stanford chips in with a cross-national brotherly example too. “Chris Nurse (ex-Aldershot Town, Tamworth and Puerto Rico Islanders) played for Guyana, while his older brother Jon (ex-Dagenham & Redbridge and Stevenage Borough) played for Barbados.

And how about the Boateng brothers? Kevin-Prince has represented Ghana, while his half-brother, Jérôme, is a Germany international.

Bossing the FA Cup without ever lifting it

“Which manager has won the most FA Cup games without ever lifting the trophy?” ponders Steven Wild.

Chris Rawson thinks it has to be ‘Ol Big Head: “From Brian Clough’s early beginnings at Hartlepool United in October 1965, to the last sad few weeks at Nottingham Forest in May 1993, the great man’s various teams won 40 FA Cup ties over that period. He only ever managed one team in a final, the infamous 1991 game, in which Paul Gascoigne was carried off, and Tottenham won 2-1 after an own goal from Des Walker.”

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“Cesc Fàbregas is linking up really well with Dennis Bergkamp, a man old enough to be his father,” wrote Rob Coke, in August 2004. “What is the greatest age difference between two team-mates in English football?”

Cesc Fàbregas (17) and Dennis Bergkamp (35) dovetailed gloriously in Arsenal’s storming start to the 2004-05 season. But they were nowhere near the record. In the absence of any cold, hard facts on the subject, we had to settle for a couple of examples: during USA 94, Roger Milla (42) and Marc-Vivien Foé (19) lined up alongside each other for Cameroon. But no tale of old and young team-mates would be complete without the word ‘Beasant’: Big Dave (43) and Leighton Baines (17) both took part in Wigan’s LDV Vans Trophy defeat to Doncaster in November 2002.

Can you help?

“Which other players have ‘done a Kepa’ and refused to be substituted,” wonders George Jones.

The Tin Boonie (@TheTinBoonie) It's not uncommon to see a player ask to be substituted due to injury, but has a player ever sought to come off because they're just playing really badly?

“Leicester’s sacking of Claude Puel has left loanee signing Youri Tielemans in an unusual situation,” begins Padraic McCafferty. “The Belgian played under both Leonardo Jardim and Thierry Henry at Monaco and will soon be playing under his fourth club manager in a single season. Has there ever been a player who has played under as many?”

Niki Halsey (@NikiHalsey76) What’s the most random bit of background action of football on TV in a movie? I have just seen Julian Joachim playing for Aston Villa in the background of Hannibal.

“I’m a (very) amateur footballer, and was recently forced to sub myself off having suffered a migraine attack during a floodlit evening game. Does anyone know if this has ever happened to a professional footballer?” wonders Charles Rozier.

Christine Camillo (@mlle_c_camillo) Has a game ever been abandoned due to lack of footballs? (Question inspired by how often they were punted out the ground at Dumbarton v Raith Rovers last night.)

Email your questions and answers to knowledge@theguardian.com or tweet @TheKnowledge_GU.