Complex sentence: After the second loss to Ali, Liston took a year off from boxing, returning in 1966 and 1967, winning four consecutive bouts in Sweden, co-promoted by former World Heavyweight Champion Ingemar Johansson.
Split into simpler sentences: After the second loss to Ali, Liston took a year off from boxing. He returned in 1966, winning four consecutive bouts in Sweden, co-promoted by former World Heavyweight Champion Ingemar Johansson.