Off the shelf racquets are NOT matched racquets.
EX: you get a batch of 3 brand new Babolat racquets. All the same model, grip size, etc.
If the swingweight is advertised to be 300 kg/cm2; the actual measurement could be anywhere from 293-307 kg/cm2.
If the overall weight is advertised to be 300 grams, the true measurement could be anywhere from 293-307 grams.
If the balance point is advertised as 6 points head light, in reality it could be 3-9 points head light.
It is my expertise I can match all the racquets to the same stats.