Start with the denominator
A close rate needs a definition: which opportunities, which period, and what counts as sold? Count one replacement decision consistently; multiple options on one proposal should not silently become multiple opportunities. A percentage by job count and a percentage of quoted dollars are different measures.
The remaining estimates
Illustrative example: 100 distinct opportunities and 60 sales give a 60% close rate under that definition. The remaining 40 could contain final declines, later decisions, open questions, and people who never responded. The percentage alone does not tell you the mix.
The useful next question
Ask: “For the estimates that did not sell, how many have a customer stated reason, and how many are still unknown?” Keep closed decisions separate from open work. Then examine whether actionable estimates have a responsible person and a next step.
What a change can establish
Better reason coverage can make the unsold side easier to understand. It does not, by itself, prove better selling or additional revenue. Compare sales on a consistent basis, note changes in lead mix and timing, and distinguish an observed change from evidence that your process caused it.