A path rule knows where a file lives and nothing more. The change map matches changed files against path rules to assign a criticality tier, and the tiers belong to the viewer rather than to the repository [9]. So a one-line change to a permission check that happens to sit in a low-tier directory sorts below the files the reviewer has already discarded [13]. Directory-shaped risk models have always had that hole. It widens when the diff came from an agent rather than from the person who chose the layout.
The tier counts in the post's own screenshot are worth converting. Fifty-four percent of the files on that pull request landed in the low tier, thirty percent in critical or high, and eleven percent in a bucket the rules could not classify at all [15][17][16]. The third figure is the adoption cost you can see from outside. Every unmatched path is a rule somebody writes, and rule sets rot at the rate the repository gets reorganised.
For the low-tier share to transfer to your repo, directory structure has to be a decent proxy for risk: tests kept out of logic, no shared helpers directory holding the rate limiter. A repo with that property probably already has reviewers who skim accurately by hand, which is what the interviewed seniors describe doing, reading the data model, the service contracts and anything touching money or identity first, and leaving helpers and tests until attention has gone [6][8]. One CTO wrote the sequence out in Slack: check nothing has been dumped into the data models, check the contracts between microservices are unmodified, then look at coherence and readability [7].
What the material does not contain is a measurement. The framing assertion is that nobody, at any skill level, can build a global understanding of a 2,000-line AI-generated PR touching 100 files [4], and that PR size grew significantly this year, with no figure attached [1]. The claim that removing the writing bottleneck moved it to review is one engineering manager's quote [3], in a post by the team building the review surface. The reported outcome of the change map is that users do like it [13], and the nearest thing to a time saving is a lead architect saying he can now see in a minute whether a PR touches critical files [12]. That is a claim about how attention gets allocated, not evidence about which defects got caught.
Reviewers also told the team they feel uncomfortable at first saying explicitly that they are not reading a file [13]. That discomfort is the most informative result here. The skim already existed; the tier list turns it into a stated decision, and stated decisions get argued about in a way that habits do not.
The number that would settle this is escaped defects by tier: bugs found after merge in files the reviewer discarded, against bugs found in files read closely. The available text ends before reporting anything like it [19]. A team running the change map for a quarter would have it.
