Sorry for the late post. Trying to get rid of a head cold. Ugh.
Haven’t run into any flat-coat mixes before. He almost looks like a pure border collie, but he doesn’t quite have that ridiculous ‘eyes boring into your soul’ intensity that a pure border collie tends to have. His dad says he’s calmer than a pure border collie, too, which is funny: flat coats tend to be a bit hyper and puppyish, and border collies are energetic, active, and can end up neurotic if they don’t get enough mental (and physical) exercise. And the combination is calmer than either one alone? Don’t look at me, I’m not Mendel.
He lives less than two blocks from my house, and I’ve been taking pictures for almost a year and a half now, and I’d never seen him yet. There are a lot of dogs in San Francisco.
(Edit: Added the pup’s name. For more info about him, check out the comment from his dad, in the comments section.)

This guy came from a border collie rescue, but you couldn't tell it by his attitude.

From the side, he looks like he's just black with tan socks, but he has that white chest and belly hidden away.

The famous 'baroo' puppy head tilt! He clearly doesn't quite know what to make of me.

Dogs do such goofy things with their tongues. I should make that a tag: dogs doing goofy things with their tongues.