the window is just for the graph - whatever extent it bases the estimate on is unchanged by the length of time you view. EDIT : NOPE, wrong about that.

i set the window to that specific time frame because i made some methodology changes that slightly affected strava’s power curve display - and maybe the actual data. long story but the app that i use (cadence) stored milliseconds in the GPX file, which amazingly caused strava’s power over time curves to be way off, because the time values were scaled by 1.2-1.5x! the app maker updated the app to output whole seconds only and i reuploaded going back in time… then got tired of it. so i keep the curve display limited to the last 11 months. i don’t think the power estimate uses data older than that - but it could. i’d wonder if that could account for the higher value but it’s actually gone up over the time period, not down.