Wikipedia - Primera B de Chile

Campeonato Primera B (English: Chilean First B Division) is the second tier in the Chilean football league system, and is organized by the Asociación Nacional de Fútbol Profesional. It was established in 1952 as Segunda División, and later renamed in 1996 to the current name. Since 1954, automatic promotion to and relegation from Campeonato Nacional has been granted, although Palestino and Rangers were promoted to the top flight in the first season.

The Chile Primera B, officially known as the Primera B de Chile, is the second tier of professional football in Chile. Established to serve as a competitive platform below the top-flight Chilean Primera División, the tournament features a diverse array of clubs vying for promotion to the top division. The league typically comprises around 12 to 16 teams that compete throughout the season, which usually runs from early in the year to late in the year. Teams play each other in a round-robin format, earning points for wins and draws. The top teams at the end of the season earn promotion to the Primera División, while the lower-ranked clubs face relegation to the third tier. The Primera B is known for its passionate fan base, competitive matches, and its role in developing future stars of Chilean football. It serves as an essential stepping stone for clubs and players aiming to reach the highest levels of the sport in Chile.