The Spanish League or LFP (Liga de Fútbol Profesional 'Professional Football League'), one of the most important domestic competitions in Europe, is composed by very competitive teams and some of the finest football players. Its origins date back to the 20s. After the brilliant participation of the Spanish national squad in the Olympic tournament celebrated in Antwerpen (Belgium), there was a football fever in Spain and the fans were eager for a better competition than the Cup (too short) or regional championships (too local). Thus, a new idea arose to create a tournament based on regularity, so that all teams could play against each other, home and away.
In 1929, the Spanish Football Federation reached an agreement with the most powerful teams of the country to create the National League Championship, originally divided in two divisions with ten team each. The initial First Division (Primera División) of Spanish football was composed in season 1929 by the following teams: Athletic Club de Bilbao, Real Madrid CF, FC Barcelona, Arenas Club (Guecho), Real Unión Club (Irún), Real Sociedad de Fútbol (San Sebastián), RCD Español (Barcelona), Athletic Club de Madrid, CD Europa (Barcelona), and Real Racing Club de Santander. The Second Division included Sevilla FC, Iberia SD (Zaragoza), CD Alavés (Vitoria), Real Sporting de Gijón, Valencia FC, Real Betis Balompié (Sevilla), Real Oviedo FC, RC Deportivo de La Coruña, RC Celta (Vigo), and Racing Club de Madrid. From that moment, the Spanish League was more and more successful every year, until it became the most important domestic competition, instead of the most traditional Cup tournament.
The main information sources used in the creation of these files are the following: newspaper "Marca" (1942-), newspaper "As" (1967-), newspaper "El Mundo Deportivo" (1941-), newspaper "ABC" (1902-), and different Internet sites. From 1985 on, when I started to collect my first statistics on paper, the information is also based on my own experiences and memories as a football fan.
For each season, I used Excel to check the scores included in the crosstable with the final classification (which in time has been compared with other classifications from different sources), so it must be assumed that they are correct. However, the scores included in the competition calendar are taken right from the newspapers, so their coincidence with the former is not completely guaranteed due to some possible publishing mistakes in the sources (I will appreciate your corrections in case you find any of these mistakes).
For visual convenience, from season 1985-86 on the scores in the crosstable are marked in black (home team wins), green (ties), and red (home team defeats).