In this talk, we present an algorithm that, assuming good network conditions, reliably determines in less than a minute whether a proposed block will always be part of the canonical chain. This represents a considerable speedup compared to waiting for the full security guarantees provided by block finalization, which takes 13 minutes in the best-case scenario. Also, this algorithm provides a far better metric than chain depth, which some services still use. Paper https://arxiv.org/abs/2405.00549