Your team already knows which leads convert — the knowledge is just buried in last year's spreadsheet. This playbook mines historical lead outcomes for the signals that actually predicted a win, turns them into a weighted scoring rubric, and validates it against a holdout month before anyone routes a single lead by it.
Workflow area: Sales · Tier: Advanced · Hands-on time: ~45 minutes
Most lead-scoring rubrics are folklore: someone senior once said enterprise leads from webinars are good, so webinars get 20 points. Working from your own outcome data replaces folklore with evidence — and the validation step tells you honestly whether the rubric beats the coin-flip you are currently using.
Prepare an anonymized export. From your CRM, export closed leads from the last 12 months with: lead source, industry, company size band, job seniority of contact, country/region, engagement signals (demo requested, pricing page, event attended), days to first response, and the outcome. Delete names, emails, phone numbers and company names before the file goes anywhere near an AI tool — the pattern analysis needs attributes, not identities. Split it: the oldest 11 months as the training set, the most recent full month held out for validation.
Ask for patterns, not a rubric, first. Upload the training set to ChatGPT (with data analysis) or Claude:
This CSV contains anonymized closed sales leads with attributes and
outcomes (won / lost / disqualified).
Using actual computation on the data (not estimation):
1. For each attribute, show the win rate per value with the count
of leads in each group (e.g. "source=webinar: 18% win, n=112").
2. Flag any group with n < 20 as "insufficient data".
3. List the 5 attributes where win rates differ most across values.
4. List anything surprising — attributes with NO relationship to
outcome that people might assume matter.
Do not build a scoring model yet. Show the tables.
Spot-check two or three of the computed rates yourself with a pivot table or COUNTIFS in Excel. If the model's numbers don't reconcile with yours, stop — it is estimating instead of computing.
Draft the rubric from the verified patterns.
Based only on the win-rate tables we verified above, propose a
lead-scoring rubric:
- 4 to 6 criteria maximum, each tied to an attribute with a real
win-rate difference and n >= 20.
- Points per criterion proportional to the strength of the signal.
- Total score 0-100, with suggested bands: A (route immediately),
B (standard queue), C (nurture).
- For each criterion, cite the win-rate evidence it is based on.
- Explicitly list attributes you EXCLUDED and why.
A good rubric line reads like evidence, not opinion:
Demo requested: +30 pts (win rate 34% vs 9% baseline, n=87)
Company size 200-1000: +15 pts (22% vs 11%, n=140)
Source = purchased list: -10 pts (3% win, n=95)
Screen for proxy bias before anything else. Ask: "Could any criterion act as a proxy for a protected characteristic or unfairly penalize a legitimate segment?" Region and seniority scores can encode bias; a criterion like "responded within one day" may just measure your team's behavior, not the lead's quality. Cut anything you cannot defend out loud to the sales team.
Validate against the holdout month. Score every lead in the held-out month with the rubric — a simple Excel formula, no AI needed — then compare: what share of that month's actual wins scored in band A? What share of band-A leads actually won versus band C? A useful rubric concentrates wins meaningfully in A. If A and C win at similar rates, the rubric is decoration; go back to step 2 or accept that your current attributes don't predict outcomes.
Implement in Excel with the rules visible. One sheet: criteria, points, evidence note, and the SUMIFS-style scoring formula. Reviewers should be able to see why a lead scored 75 — a rubric no one can inspect is a rubric no one will trust or correct.
Lead exports contain personal data — names, emails, phone numbers of real people, which fall under DPDP and, for EU contacts, GDPR. Strip all identifiers before uploading to any AI tool, use your organization's enterprise tenant, and remember the analysis needs attributes and outcomes, never identities. pb-12 covers the full pre-flight.
The holdout validation is the playbook. Anyone can generate a plausible-looking rubric in five minutes; only the held-out month tells you whether it predicts anything — and a rubric that fails validation honestly is worth more than one that ships on vibes.