Understanding Your Grade
Your grade evaluates the geometric perfection of the thumbstick module's outer boundary.
A+ (Esports Ready) means the stick achieves a flawless circle, critical for consistent diagonal movement in games like Apex Legends and Rocket League.
F (Defective) indicates severe asymmetry, meaning diagonal inputs will hit their max value prematurely or not at all.
Since you're using a Nintendo Switch Pro with a Potentiometer module, you can expect the underlying tech to be prone to slight asymmetry and physical wear.
The Switch Pro Controller's stick sits in a snug, closed gate, so housing friction adds noise near the rim and can make a healthy stick look slightly less circular than it is. Before concluding the module itself is asymmetric, clean the gate with a cotton swab and isopropyl alcohol and re-run the test — debris under the stick collar is a frequent cause of rim wobble on Pro pads.
Potentiometer (pot) sticks read position from a wiper sliding over a carbon track, and that friction is exactly where circularity degrades over time. A fresh pot module can trace a near-perfect circle, but as the track wears, the wiper loses contact at certain angles and the ring starts to pinch into a squircle — usually first visible near the 45-degree diagonals. Wear is rarely symmetric between the X and Y axes, so a lopsided grade on a pot module is the classic signal that the stick has been played past its best range and is a stronger candidate for replacement than for recalibration.
Pot modules degrade along a predictable path: the carbon track wears where the stick spends the most time, so the ring pinches first at your dominant input angles, and the wiper's lost contact produces small flats on the circle before full drift appears. Because the wear is physical, no software setting can restore the geometry — recalibration only recenters the zero point, it cannot grow the worn track back. A lopsided grade between the X and Y axes on a pot module is therefore the most reliable hardware-wear signal this tester can show, and the replacement decision is generally clear once the ring shows a visible flat.
On the Switch Pro, the snug gate means the reading is a mix of sensor and housing behavior, so a mediocre grade should trigger a cleaning pass before any conclusion. If the ring improves after cleaning, the module is fine and the friction was housing debris. If a Pro pad still grades poorly after cleaning, the usual cause is a worn stick collar that lets the stick tilt off-axis — that produces a consistent oval on one axis, which is mechanically distinct from the squircle pattern seen on Xbox pads.
The Pro Controller's compact stick module is shared with the Nintendo Switch Joy-Con platform lineage, and that family is known for early stick degradation reports, so a poor grade on a Pro pad deserves more weight than the same grade on a newer Hall-effect unit. The snug gate also means the stick collar friction shows up directly in the rim data, which can obscure a genuinely healthy sensor beneath housing noise. Clean the collar first, grade again, and only then compare the result against the model's typical behavior — a clean ring after a debris-free pass is a strong signal the module itself is fine.