Complex sentence: He was assigned to work the 1997 NLCS between the Florida Marlins and Atlanta Braves, and was behind the plate for Game 5 as Liván Hernández, the young Florida pitcher, struck out the two-time defending NL champions 15 times, establishing various records.
Split into simpler sentences: He was assigned to work the 1997 National League Championship Series between the Florida Marlins and Atlanta Braves. Gregg was behind the plate for Game 5 as Livan Hernandez, the young Florida pitcher, struck out the two-time defending National League champions 15 times, establishing various records.