Miners & forgers
How concentrated is block production? Each block has a FORGER (the plot owner — pocx_account_id) and a SIGNER (the address that signed the header — signer_address). They're usually the same, but pools' create_assignment lets one signer cover many forgers, so the difference between the two distributions reveals pool consolidation.
Top forgers (by plot)
Unique plot owners — pocx_account_id grouped over the visible window.
Top signers (by signing address)
Block-signing addresses — signer_address grouped over the visible window. Pools surface as concentrated rows.