Carli's father Chico scored the highest ever in O.G. Bierstadt's history. Still true to this day. I couldn't recall the scores so I asked Angie who sent this file earlier.
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Chico was AD, BH, SchH1, SchH2, SchH3 (4 times), IPO 3 (2 times), certified Police Dog. He didn't place at nationals.
In Schutzhund 300 is the potential. There are only two GSD's who ever scored 299 (Enno and his son Drigon). The only dog bettering that was a Rottweiler who had a 300 in the early 90's (Pascha Vom Hegestrauch).
Here is Drigon in Hannover when he scored 299. First video is obedience (100) and tracking (100). The second is protection (99).
Many of the top dogs worldwide score in the 290's. To score high they need lots of active aggression (fight drive), yet must be very trainable and also a thinking dog. It must be in their genetic inheritance going back generations.
ETA: Chico was always around kids and very loving. Active aggression applies to the "working" part of working dog.