Upside down glass of water experiment revisited

A glass of water covered with a disk with a hole in it can be turned upside down without spilling the water in the glass, provided the hole is small enough and the disk is pressed against the rim of the glass. A quasistatic numerical simulation based on hydrostatic pressure and surface tension of water was used calculate the critical hole diameter when the water will begin to drain. The model predicts a critical hole diameter of 15.25 mm. Experimentally it was found tha a hole diameter of 15.1 mm was still small enough to keep the water from draining.