Defending champion Jason Day and world No. 1 Dustin Johnson headline a stellar field at the WGC-Dell Technologies Match Play. Here is what You Oughta Know heading into golf's version of March Madness.
• Third year of pool play format in this event; second year held at Austin Country Club
• Defending champion: Jason Day (only one player has successfully defended, Tiger Woods 2003-04)
• Top overall seed: Dustin Johnson (won last two worldwide starts, Genesis Open and WGC-Mexico Championship)
• No. 1 overall seed has won four times (Woods three times and Rory McIlroy in 2015)
• Lower seed has won 39.