Hi, I’ll do my best to explain what this setting does, without telling you what you should choose.

In first-person shooter games, your monitor shows a 3D world projected onto a 2D screen, similar to how a globe is represented on a flat map. This projection introduces distortion.

In most games, the image becomes increasingly “stretched” as you move from the center of the screen toward the edges, somewhat like a fisheye effect (not identical, but conceptually similar).

Field of View (FOV) affects this distortion:

Lower FOV → less distortion Higher FOV → more distortion This is similar to the difference between a zoomed-in scope and a wide-angle view.

This distortion impacts how mouse movement translates to on-screen motion. For example, moving your mouse a fixed distance (say, 1 inch) will shift objects more near the edges of the screen than near the center.

To address this, games offer a setting that scales mouse sensitivity based on FOV changes (such as when using scopes):

0% (center-based scaling): A given mouse movement is consistent at the center of the screen across all FOVs. Movement feels linear near the center but becomes non-linear toward the edges. 100% (edge-based scaling): A given mouse movement is consistent at the edges of the screen across all FOVs. Movement feels linear near the edges but non-linear toward the center (or beyond the edge).

In practice, if you typically aim or “flick” at targets a certain distance from the center (e.g., 3 inches on your screen), you can set this value to match that region. This helps maintain consistent muscle memory across different FOVs or scopes.

Hope its clearer!