What is "SAM Score"?

The suggested action metric (SAM) score is a single number meant to help maintainers of open-source repositories get an at-a-glance health check for their repo.

The formula for SAM score is simple:

// Simple ratio: what percentage of all issues ever are still open?
let open_ratio = (open_issues / open_issues + closed_issues)

// Scale: how many total issues have you ever had?
let scale_factor = (open_issues + closed_issues)

// SAM score is the ratio of open to closed issues multiplied by a logarithmic
// scale factor.
let score = open_ratio * Math.log(Math.E + scale_factor)

The goal is to get the lowest SAM score possible without "gaming" the system through bug bankruptcy or other developer-unfriendly processes.

The basic principles are:

• Open issues are bad, closed issues are good.
• 100 out of 200 issues open is worse than having 1 out of 2.
• Repos with more issues require more attention, but not linearly so.

SAM Scores fall into the following buckets:

• < 0.5 - Excellent
• < 1.0 - Good
• < 2.0 - Okay
• > 2.0 - Poor