[ani-ani]

"To crack an egg open, you first need to dent it. When the egg loses its curvature, it loses its strength."

I felt like this part could use some fleshing out. I'm pretty sure that the egg does not lose its strength because it "loses its curvature", tough I must admit I'd be hard pressed to provide a more precise explanation. I would say it has more to do with the "hand wrap" spreading out the force over a wide area, so that the egg's curvature causes the hand's force to work against itself. But a small discontinuity creates a focus point where the force will be localized, causing successively more breakage in the shell.

[mcnamaratw]

The article is accurate. A piece of paper can bend without tearing. An eggshell can't. The difference is the shape. https://en.wikipedia.org/wiki/Gaussian_curvature