Your forecast is a hygiene report
When a CEO says "the forecast was off by 40% last quarter," the cause is almost never the model. It's that a third of the pipeline was dead deals nobody closed out, close dates that had slipped six times, and placeholder amounts from eight months ago.
The seven rot patterns
Zombie deals — no activity in 30+ days, still counted in coverage. In most orgs I audit, 20–40% of open pipeline. Time-traveling close dates — close dates in the past on open deals; trivially preventable, almost universally present. Serial slippers — deals whose close date moved three or more times; each slip is a loss the rep already knows about…
The full playbook covers all seven patterns with the exact report to run for each, what the rot costs in forecast credibility, rep time, and diligence risk — and the nightly/weekly/monthly system that keeps orgs clean permanently.