We give a necessary and sufficient condition for the addition of a collection of disjoint bypasses to a convex surface to be universally tight – namely the nonexistence of a polygonal region which we call a virtual pinwheel.
"Pinwheels and bypasses." Algebr. Geom. Topol. 5 (2) 769 - 784, 2005. https://doi.org/10.2140/agt.2005.5.769