What stick drift actually is
Stick drift is a resting report: the analog stick tells the game it is moving while your thumb is off it. That is different from a noisy live plot while you are circling the rim. A tester that only draws a dot cannot tell those two stories apart, which is why so many “my controller is broken” threads start with a screenshot of someone still holding the pad.
CTRLCHK’s drift test is a centre-only protocol. After a 3-2-1 get-ready countdown you leave the controller on the desk for five seconds. Samples collected before the countdown are discarded. The statistic that decides whether the capture is valid is jitter around the median rest — not distance from (0, 0). A DualSense that rests a little off centre is a drift result. A DualSense you were still holding is an invalid capture, and the UI will say so instead of inventing a failure.
How the deadzone is calculated
Games ignore a disc around centre called a deadzone. Too small and residual drift walks your aim. Too large and you lose fine aiming. Our estimate is resting P95 plus a 1.5% safety margin, clamped to 35%. Near-zero rest (P95 at or below 3%) returns 0%. That number is a starting point for in-game settings, not a claim about what the hardware “should” do.
You will see both sticks independently. Left and right wear differently, especially on games that sprint with the left stick and aim with the right. Type each percentage into the matching in-game slider. If the game only offers one stick deadzone, use the worse of the two.
Repair versus replace
CTRLCHK currently treats P95 resting movement at or below 3% as a low observed offset. 3–6% is usually playable with a small deadzone. 6–12% is the zone where a hall-effect module or a cleaning pass is optional but a deadzone will restore a stable centre. Above that, a deadzone is a mask: the mechanical rest has moved, and stick-module repair or a new pad is the honest advice under measurement model 3.0. CTRLCHK prints that sentence next to the score so you are not left translating a color bar.
Experiencing a kick in the opposite direction when releasing the stick? Run the Snapback Test. To try in-game settings against the same rest sample, use the deadzone test. For a full picture — range, circularity, buttons and triggers — run the guided gamepad tester. Drift alone answers the question most people actually arrived with.