Inspired by this question, what is the record for the maximum number of times two teams have actually faced off in one season? Since league formats vary across countries and continents, I have restricted the scope of this question to the Big Five leagues of Europe (i.e the English Premier League, Spanish La Liga, Italian Serie A, German Bundesliga and French Ligue 1).
There have been 7 El Clásicos played between Real Madrid and Barcelona during the 2010/11 season in 4 different tournaments:
- 2010/11 La Liga:
29.Nov.2010 BAR 5 - 0 RMA
16.Apr.2011 RMA 1 - 1 BAR
- 2010/11 Copa del Rey Final
20.Apr.2011 RMA 1 - 0 BAR
- 2010/11 UEFA Champions League Semi-Final:
27.Apr.2011 RMA 0 - 2 BAR
03.May.2011 BAR 1 - 1 RMA
- 2011 Supercopa de España*:
14.Aug.2011 RMA 2 - 2 BAR
17.Aug.2011 BAR 3 - 2 RMA
7 is actually just one below than maximum 8 games that 2 Spanish sides can play each other during a single season. In this case if sides were matched earlier than in Copa del Rey Final, they would have reached this threshold.
*Spanish supercup games are played in 2 legs. 2011 edition was played between 2010/11 La Liga winner and 2010/11 Copa del Rey winner.