Contrary to the name, this is not the perfect game stamp.
Ingame stamp description:
Perfect Target: Hit the center of the target area and score 100 points with all ten of your throws. Extra points scored by popping balloons don't count. You can't get this stamp in team play.
Strategy:
Not as hard as it sounds. Because the dog catches them out of the air before they go past the bull's eye, there is a lot of leniency with your throws. Ignore the balloons and throw however you're most comfortable. I have a preference for curved throws they seem more consistent.
Difficulty: 3/5
Wii Sports Resort All Stamps Playlist:
• Wii Sports Resort (Wii) | All Stamps