How does Kaspa calculate a block's Blue Work score?

A block's Blue Work score is built by inheriting its Selected Parent's accumulated Blue Work, then adding the Blue Work of any blue blocks in its Mergeset. The Selected Parent is the most recent consensus block a new block directly builds on — think of it as the block's main ancestor. The Mergeset is the collection of recent parallel blocks the new block also merges in. If a block in the Mergeset is red, its work is simply ignored. Only blue Mergeset blocks get their work counted. This design ensures that every block's security score honestly reflects only agreed-upon history, so attackers cannot pad a chain's apparent strength with rejected blocks.