Complex sentence: The EMSBL (East Meadow Strat-O-Matic Baseball League), founded in 1972, is believed to be the oldest continuously playing fantasy baseball league in the world which plays the baseball version of Strat-O-Matic.
Split into simpler sentences: The EMSBL (East Meadow Strat-O-Matic Baseball League), founded in 1972, is believed to be the oldest continuously playing fantasy baseball league in the world. It plays the baseball version of Strat-O-Matic.