3D-pop is not measurable but can be felt every now and then.
I saw funny theories about that, associating 3D pop with leaded glass for instance. Boring, unfounded stuff comparing apples with oranges to make a point, the kind internet is full of.
My feeling (not based on serious statistical work): it is likely to happen on pics shot at rather wide apertures, with directed rather than diffuse light, and a physically deep scene, provided the lens is sharp and contrasty at said wide apertures. Colour contrast also contributes, helped by the fact that the eye "sees" different colors at different distances (bright red seems to be behind other colors for instance, or is it the contrary).
Optics emphasizing contrast (Zeiss lenses in general) may produce such "pop" impressions more often than others. Vignetting (often high with Zeiss, again) may also contribute. Techniques for increasing the blur off-focus (tilt, etc.) are a different story.