i would say theres much truth in this when the bird is completely moulted off course,, to me this would show a good moult and a well balanced pigeon also, in good condition,,,
strange thing is we all know that a racing pigeon has 12 tail feathers,, so their cant be a" middle one", so to see only one feather , as mentioned, one must over lap the other, either the left middle or the right middle , ,, in looking at many birds ,some have the left middle tail feather overlapping, some have the right middle tail feather overlapping,,, ,,, ive often wondered why,, :)