Press Ctrl+M to hide or show the YouTube video player controls.

When you pause a YouTube video, the player controls don't disappear. That makes it really hard to take a clean screenshot of the video. The controls also block your view, which can get really annoying. Hyde is a simple Chrome extension that allows you to hide or show the video player controls easily. 

- Simply use the keyboard shortcut Ctrl+M to hide the controls or show them again. -"