Complex sentence: The National Open Pairs was the first national bridge championship for open pairs and was held at the fall American Contract Bridge League (ACBL) North American Bridge Championship (NABC) as a four-session matchpoint (MP) pairs event.
Split into simpler sentences: The National Open Pairs was the first national bridge championship for open pairs. It was held at the fall American Contract Bridge League (ACBL) North American Bridge Championship (NABC) as a four-session matchpoint (MP) pairs event.