open-pstack — arena: N candidates, a cross-judge after all are terminal, then a hand graft Diagram

Same prompt, different models

the prompt is the contract; the rubric stays with the parent
convergence is strong agreement; wild divergence means reframe

Judge after terminal

the cross-judge prefers a provider other than the parent and the likely base
the parent still reads every candidate and scores criterion by criterion

Graft by hand

one or two parts per losing candidate, folded in under one mental model
a dropout leaves N-1 candidates and is named in the synthesis note