Unreviewed PRs merged
Unreviewed PRs can be detrimental. From not having a feature complete releases to bug ridden releases, unreviewed PRs can negatively impact the entire process, product, and the company. The reasons why PRs are merged without reviews can range from high workloads, to large PR size, and many more.
This is an important metric to not only gauge the quality of your process but is often the reason why teams have deceptively very low cycle time. Even though low cycle time is desirable, having very low cycle time of less than a few hours is often a signal of compromise on process quality either through merging unreviewed PRs or a low quality of reviews. This metric represents the count of PRs that were merged with a review. This includes not only PRs that were not approved but also those that were not reviewed at all.