Reading the benchmark
It measures frame times while you play your own game, not a synthetic scene. What the percentiles mean and why the average is the least useful number on the page.
Reading the latency testWhat the colours mean, what a good result looks like, and — the part most tools get wrong — what this number is not.
Why the test asks for 12 seconds of mouse movementNot an arbitrary number. Here is what 12 seconds buys that 3 does not, and why it needs your real movement rather than a synthetic one.
What the stutter scan looks forIt looks for the causes that leave a trace, tells you which ones it found, and does not invent a cause when it finds none.