Reserve 4 perfect strawberries.
Puree the remaining strawberries in a food processor or blender.
Add the Chambord, if using, and sugar.
(If the berries are very tart, you may need more sugar.) Chill until ready to serve.
In 4 parfait glasses or stemmed water goblets, alternate layers of yogurt and strawberry sauce.
For a garnish, press one of the reserved whole berries onto the rim of each glass (as you would lemon for iced tea).