Defending champion Walter Ray Williams Jr., Norm Duke, Michael Haugen Jr. and Ron Mohr are among the 16 unbeaten players after Friday’s first day of match play at the 2018 United States Bowling Congress Senior Masters at Sam’s Town in Las Vegas. Williams, who has three seconds already on the 2018 PBA50 Tour, is looking to become the first person since Tom Baker in 2007 to successfully defend a USBC Senior Masters title and the event's first three-time winner — he also won in...