Complex sentence: An additional practice session the next morning with Hélio Castroneves posting the best times, followed by "shootout" qualification rounds later in the afternoon to determine pole position and the starting positions of the rest of the field.
Split into simpler sentences: An additional practice session was held the next morning with Hélio Castroneves posting the best time. The format was for "shootout" qualification rounds later on Saturday afternoon to determine pole position and the starting positions for the rest of the field.