Stages
An Opportunity is always at one stage. A new one starts at Qualified.
Entering a stage sets the Opportunity’s probability and forecast category to the stage’s starting values. You can set your own figure on an opportunity, and it holds until the stage next changes. No bid is its own outcome, so it never counts against your win rate.
An Opportunity that has sat at an open stage for longer than usual is marked as late. By default that is 30 days at Qualified, 21 at Proposal and 14 at Negotiation, and an Admin can change them.