Basque derby

In January 2018, [[Iñigo Martínez]] made the same move, with his transfer only made possible by Athletic paying his €32 million contractual [[release clause]] amount, making it impossible for Real Sociedad to reject the approach.{{cite news|url=http://www.athletic-club.eus/en/news/18697/inigo-martinez-jokalaria-fitxatu-du-athletic-clubek.html|title=Iñigo Martínez signing|publisher=Athletic Bilbao|date=30 January 2018|access-date=30 January 2018}}{{cite web|url=http://www.goal.com/en/news/athletic-bilbao-sign-martinez-from-real-sociedad/g2qcqw6nfa8t1fj74qrh862fb|title=Athletic Bilbao sign Inigo Martinez to replace Aymeric Laporte|publisher=Goal.com|date=30 January 2018|access-date=30 January 2018}} In turn, the buying club only had the sufficient financial means due to receiving approximately double that amount the same day for [[Aymeric Laporte]] who moved to [[Manchester City F.C.|Manchester City]], also via his release clause.{{cite web|url=https://www.bbc.co.uk/sport/football/42873612|title=Aymeric Laporte: Manchester City sign French defender for club-record £57m|publisher=[[BBC Sport]]|date=30 January 2018|access-date=30 January 2018 }} Real Sociedad's response to the defection of Martínez – who had previously been quoted as saying he would never move to Athletic Bilbao – was to offer a new replica jersey to all supporters who presented an older one with his name on the back at the club shops, with the process titled 'He's history'.{{cite news|url=https://as.com/futbol/2018/02/02/primera/1517603322_973793.html |title=Gran respuesta al intercambio de camisetas de Iñigo Martínez |trans-title=Great response to the exchange of Iñigo Martínez shirts |language=es|newspaper=Diario|date=2 February 2018|access-date=3 February 2018}} In addition to being the most expensive move between two Basque clubs, the Martínez fee was the new record for spending by Athletic (the Laporte deal became the record amount received by them); Real Sociedad had received slightly more in 2013 when [[Asier Illarramendi]] transferred to Real Madrid.{{cite web|url=http://www.goal.com/en/news/11/transfer-zone/2013/07/12/4112360/real-madrid-reveal-3219-million-illarra-fee?ICID=CP_124|title=Real Madrid reveal €32.19 million Illarra fee|publisher=Goal|date=12 July 2013|access-date=30 January 2018}}

In January 2018, [[Iñigo Martínez]] made the same move, with his transfer only made possible by Athletic paying his €32 million contractual [[release clause]] amount, making it impossible for Real Sociedad to reject the approach.{{cite news|url=http://www.athletic-club.eus/en/news/18697/inigo-martinez-jokalaria-fitxatu-du-athletic-clubek.html|title=Iñigo Martínez signing|publisher=Athletic Bilbao|date=30 January 2018|access-date=30 January 2018}}{{cite web|url=http://www.goal.com/en/news/athletic-bilbao-sign-martinez-from-real-sociedad/g2qcqw6nfa8t1fj74qrh862fb|title=Athletic Bilbao sign Inigo Martinez to replace Aymeric Laporte|publisher=Goal.com|date=30 January 2018|access-date=30 January 2018}} In turn, the buying club only had the sufficient financial means due to receiving approximately double that amount the same day for [[Aymeric Laporte]] who moved to [[Manchester City F.C.|Manchester City]], also via his release clause.{{cite web|url=https://www.bbc.co.uk/sport/football/42873612|title=Aymeric Laporte: Manchester City sign French defender for club-record £57m|publisher=[[BBC Sport]]|date=30 January 2018|access-date=30 January 2018 }} Real Sociedad's response to the defection of Martínez – who had previously been quoted as saying he would never move to Athletic Bilbao – was to offer a new replica jersey to all supporters who presented an older one with his name on the back at the club shops, with the process titled 'He's history'.{{cite news|url=https://as.com/futbol/2018/02/02/primera/1517603322_973793.html |title=Gran respuesta al intercambio de camisetas de Iñigo Martínez |trans-title=Great response to the exchange of Iñigo Martínez shirts |language=es|newspaper=Diario|date=2 February 2018|access-date=3 February 2018}} In addition to being the most expensive move between two Basque clubs, the Martínez fee was the new record for spending by Athletic (the Laporte deal became the record amount received by them); Real Sociedad had received slightly more in 2013 when [[Asier Illarramendi]] transferred to Real Madrid.{{cite web|url=http://www.goal.com/en/news/11/transfer-zone/2013/07/12/4112360/real-madrid-reveal-3219-million-illarra-fee?ICID=CP_124|title=Real Madrid reveal €32.19 million Illarra fee|publisher=Goal|date=12 July 2013|access-date=30 January 2018}}

Eight coaches have been in charge of both clubs, including [[Rafael Iriondo]], [[José María Amorrortu]], [[Javier Irureta]] and [[Javier Clemente]] who are better known for their spells with Athletic Bilbao, whereas [[Salvador Artigas]] had a more significant association with the ''Txuriurdin''; the others are [[Lippo Hertzka]], [[Antonio Barrios]] and [[Baltasar Albéniz]].{{cite news|url=http://real-sociedad.diariovasco.com/noticias/201610/13/ocho-entrenadores-ocupado-banquillos-20161013005104-v.html |title=Ocho entrenadores han ocupado los dos banquillos|trans-title=Eight coaches have occupied the two benches |language=es|newspaper=El Diario Vasco|date=13 October 2016 |access-date=16 December 2017}}

Eight coaches have been in charge of both clubs, including [[Rafael Iriondo]], [[José María Amorrortu]], [[Javier Irureta]] and [[Javier Clemente]] who are better known for their spells with Athletic Bilbao, whereas [[Salvador Artigas]] had a more significant association with the ''Txuriurdin''; the others are [[Lippo Hertzka]], [[Antonio Barrios (footballer)|Antonio Barrios]] and [[Baltasar Albéniz]].{{cite news|url=http://real-sociedad.diariovasco.com/noticias/201610/13/ocho-entrenadores-ocupado-banquillos-20161013005104-v.html |title=Ocho entrenadores han ocupado los dos banquillos|trans-title=Eight coaches have occupied the two benches |language=es|newspaper=El Diario Vasco|date=13 October 2016 |access-date=16 December 2017}}

===Scoring records===

===Scoring records===