Four things, counted on open deals: the share with no amount, the share with no next step, the share whose close date has already passed, and the gap between the best and worst rep's win rate. Across LeanScale's recent diagnostics the medians are 54%, 59%, 19% and 2.9 times. All four come from a plain CRM export.
Count them on open deals as they stand today. A close date in the past is the strongest single sign that the forecast is stale, and a blank next step usually means nobody owns the deal's next move. You can run all four on your own export on the GTM diagnostic page; the math runs in your browser and nothing is uploaded.
Every claim above comes from work LeanScale published. These are the sources.