Marshall introduces *operational skill* as distinct from moment-to-moment mastery. His definition: **operations is the coordination of tactics over time**, where tactics are individual actions. His running example: long runs, speed work, walking, leg strengthening, stretching, hydration, foam-rolling, recovery, cross-training, keeping stats and a plan — each tactic can help, but uncoordinated they do damage (overtraining breaks you down; no cohesion yields trivial gains). Operational skill is the "seemingly basic but utterly critical" connective work: scheduling, planning, communicating, checking, and adjusting periodically. The core question is "how do I ensure all the right action happens over time — over weeks, months, even a year?" If this doesn't come naturally (Marshall says it didn't for him), the move is to learn from operationally gifted people rather than figure it out alone — he constantly asks his collaborator Kai Zau, who is "so operationally sound." Cross-domain: training programs, project management, company operations, personal systems. --- *Source: [[Book Inventory/Progression|Progression]] (Sebastian Marshall, 2016) — Upstream Effects #9 — Adherence and Mastery*