The notice first published on November 13 has one more statistic. El Clasico is on 29/11 (2+9+1+1=13).
In the long history of clashes between Barcelona and Real Madrid (almost 180 games) only four matches have been held on the 13th day - and the 13th day equals a jinx for Real Madrid.
Real Madrid 4-0 Barcelona (January 28, 1934)
The first encounter on this date goes back to 1934. Valle opened the account for the Merengues, before Samitier made it two on 20 minutes.