Did you realize that if you take the best seeds, looking to the many 1000+ or any 1200+ produced by them, they came from not too many places?
723, 845, 805: New York 846, 705, 801.5: Ohio 940, 790: Oregon
Maybe is the weather, the latitude, many growers and then many chances, just luck? Of course there are others nice ones from other places, like 712 Kuhn, 1026 Holland or 875 Dill, but...