Four-twenty is a slang term for marijuana consumption. It's origin and derivation aren't 100% clear, but it is widely believed to be a reference to meeting at 4:20 PM (presumably after school) to get high. The term appears to have originated in California in the seventies, but didn't seem to get national traction until decades later. Things being what they are, and the squarest of the square wanting to be part of a winking, not-so-inside joke, it has led to 4/20 (the date of tonight's game) being sort of considered a day to celebrate pot smoking. And I guess making opaque references to it makes the guys on the air feel less square. SNY is always thinking about the kids.