Yale law professor Ian Ayres walks through Ever-Tite Roofing Corp. v. Green, a contracts case turning on when performance itself counts as acceptance of an offer. Drawn from his American Contract Law course on Coursera, the lecture sits within a unit on the bargain relationship and the ways a party can exercise its power of acceptance. Ayres works through the facts of the roofing dispute, where the contractor began performance before formally communicating acceptance, and uses it to explain the doctrinal line between acceptance by promise and acceptance by conduct. The lecture stays close to the case text, tracing how courts decide whether starting work binds a party even before notice reaches the other side. It runs thirteen minutes and functions as a focused doctrinal briefing rather than a broad survey, aimed at students working through offer and acceptance rules in a standard contracts curriculum.