Estimation.
3-point estimates (optimistic/realistic/pessimistic), risk-adjusted timelines, story sizing, complexity assessment, project timeline prediction.
PERT, Sprint Velocity, Risk Buffers.
HOW LONG WILL IT TAKE is the hardest question in software. This skill applies PERT (Program Evaluation and Review Technique): every task gets three estimates, weighted by risk profile. Sprint velocity tracking smooths the noise over time. Complexity scoring (Fibonacci 1,2,3,5,8,13) instead of hours.
Four recipes.
PERT 3-point estimates
For each task: O (optimistic), R (realistic), P (pessimistic). Expected = (O + 4R + P) / 6. Standard deviation = (P - O) / 6. Honest uncertainty in the number.
Risk-adjusted buffers
Multiply estimate by risk multiplier: 1.0 (familiar), 1.5 (some unknowns), 2.0 (lots of unknowns), 3.0 (research project). Stop pretending unknowns do not cost time.
Sprint velocity tracking
Story points completed per 2-week sprint. 4-sprint moving average smooths out individual blowouts. Use the average for next-sprint commitment.
Complexity vs effort
Story points are COMPLEXITY (cyclomatic, conceptual), not HOURS. A 13-point story might take 1 day or 1 week -- but it IS more complex than a 5-point one.
It composes.
Skills compose into workflows. Estimation is rarely the only skill you will use — it pairs naturally with these others in the library.
One command.
Installs only stryx-estimation (skip the other 19) into ~/.claude/skills/stryx-estimation/.
Free for all use.
Stryx Labs License v1.0. Use Estimation in personal, commercial, internal, and production work. No attribution required.