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Lesson
Lesson 5.3 — Story points, planning poker, and velocity (correct arithmetic)
Explain story points and planning poker, and compute velocity correctly as an empirical characteristic, not a KPI.
Story Points, Planning Poker, and Velocity
Story Points, Planning Poker, and Velocity
Story points are a unit of relative estimation. They capture the overall size and complexity of a Product Backlog item compared to other items — they are NOT hours and must never be treated as hours. A story that is twice as complex as another should receive roughly twice as many points, regardless of how many hours any individual developer would spend on it.
Planning poker is a relative-estimation technique used during refinement or Sprint Planning. Each team member privately selects a card (often from a Fibonacci-like sequence: 1, 2, 3, 5, 8, 13…), then all reveal simultaneously. Large differences in estimates trigger a discussion that surfaces hidden assumptions — which directly supports the 'Estimable' attribute of INVEST. The team reaches a consensus estimate after the discussion.
Velocity is the average number of story points the team completes over the last N Sprints, counting ONLY items that fully meet the Definition of Done. A partially finished item scores zero. Example: a team completes 20, 24, 22, and 26 points over four Sprints. Velocity = (20 + 24 + 22 + 26) ÷ 4 = 92 ÷ 4 = 23 points per Sprint.
Three common misconceptions must be avoided. First, velocity is an empirical observation — it is never a target or KPI; pressuring a team to increase velocity encourages gaming (inflating estimates) and harms quality. Second, velocity cannot be compared between teams because teams size stories differently. Third, an item contributes to velocity only when it meets the Definition of Done — partial work does not count.
Lesson notes
Story Points, Planning Poker, and Velocity
Story points are a unit of relative estimation. They capture the overall size and complexity of a Product Backlog item compared to other items — they are NOT hours and must never be treated as hours. A story that is twice as complex as another should receive roughly twice as many points, regardless of how many hours any individual developer would spend on it.
Planning poker is a relative-estimation technique used during refinement or Sprint Planning. Each team member privately selects a card (often from a Fibonacci-like sequence: 1, 2, 3, 5, 8, 13…), then all reveal simultaneously. Large differences in estimates trigger a discussion that surfaces hidden assumptions — which directly supports the 'Estimable' attribute of INVEST. The team reaches a consensus estimate after the discussion.
Velocity is the average number of story points the team completes over the last N Sprints, counting ONLY items that fully meet the Definition of Done. A partially finished item scores zero. Example: a team completes 20, 24, 22, and 26 points over four Sprints. Velocity = (20 + 24 + 22 + 26) ÷ 4 = 92 ÷ 4 = 23 points per Sprint.
Three common misconceptions must be avoided. First, velocity is an empirical observation — it is never a target or KPI; pressuring a team to increase velocity encourages gaming (inflating estimates) and harms quality. Second, velocity cannot be compared between teams because teams size stories differently. Third, an item contributes to velocity only when it meets the Definition of Done — partial work does not count.