Arema–Persib Bandung rivalry or Western Blue and Eastern Blue derby is the name given in football to any match between two Indonesian football clubs with two different league backgrounds, Persib Bandung (Perserikatan) and Arema (Galatama).
The fierce competition between both teams began in 1990 when Arema and Persib faced off in the semifinals 1990 Jawa Pos II Cup.
Both teams have groups of supporters who are equally well-known fanatics, namely Bobotoh (Persib Bandung) and Aremania (Arema).
Both supporter groups have also been known for their psywar, conducted throughout the game, making the rivalry matches much awaited.
However, the current condition is due to block-blocking that has occurred among Indonesian supporters.