Parsons will not be there at 18.
Only way that could happen is to trade down 2 3 spots, take Waddle or Smith, get second and may be third. Then turn around using the second third to move up from 18.
Only way that could happen is to trade down 2 3 spots, take Waddle or Smith, get second and may be third. Then turn around using the second third to move up from 18.