Trace option for ASP.NET control will be useful to inspect event sequence.

Sometimes to understand sequence of events in ASP.NET page, it is useful to set
@page TRACE=”true”
It shows(among other details) the sequence of page events and time that took each event to execute.
However you can’t request the same trace facility for user control events. You have to insert your own Trace.WriteLine (or similar) statements, which is quite annoying. I’ve posted the suggestion to MS Feedback site, but they do not want to implement it.
Related articles that describe events  and events order:
FAQ: Sequence that events are raised for Pages, UserControls

ASP.NET Page Life Cycle Overview (and quick sheet)

Not directly related article: Control State vs. View State Example