Complex sentence: A fight between Tyson and Holyfield for the undisputed championship was scheduled for November 8,1991 at Caesars Palace in Las Vegas, but Tyson pulled out after sustaining a rib cartilage injury during training.
Split into simpler sentences: A fight between Tyson and Holyfield for the undisputed championship was arranged for the autumn of 1991. The match between Tyson and reigning champion Holyfield was scheduled for November 8,1991 at Caesars Palace in Las Vegas, but Tyson pulled out after sustaining a rib cartilage injury during training.