To be fair, I'm an ops guy, not a search engineer. ;) It's valid to say AV might not have implemented the basic concepts as well and I don't want to devalue Google's innovation. It just annoys me when people assume PageRank was a unicorn and nobody else was doing anything similar.
As much as I value PageRank, it annoys me when people assume it was a novel idea.
It had been applied decades before through scientific paper references, as a measure to improve on the "number of references" metric, which is more easily gamed. References are more rarely circular (only same time in-preparations can form cycles, unlike web pages). I was sitting in a class about stationary processes in 1996 when the lecturer mentioned this (already old and well known at the time) use case as motivation.
Whatever AV implemented at the time, it was not on par.
