In 60 years of watching baseball, it took until Thursday night to finally put my wrinkly, crooked index finger on it. I realized what has been right in front of me the past five seasons: Yankees catcher Gary Sanchez, a two-time All-Star, knows almost nothing — nothing — about how to play baseball.

It seem as if several times per game he shows himself to be totally unfamiliar with the sport, beyond swinging as hard as he can to try to hit home runs.

Everything else either throws him or escapes him.

Thursday against the A’s in Oakland, Sanchez led off the second with an, oops, line-drive single. The next batter, Brett Gardner, hit a hard grounder to first — the ball’s first bounce was immediate, just a few feet beyond the plate — yet Sanchez was seen running toward second at a minimized pace because he was looking back toward first.

What did he expect to see at or near first? I don’t know. A pink flamingo?

If he wanted to see a force play on Gardner, he did. But why he didn’t head directly toward second on a ground ball was more hard evidence that Sanchez doesn’t know enough about baseball to know how it should be played.

With the throw from first now headed toward second, Sanchez only needed to slide to beat that throw — it would be high and wide — as the force was no longer in play.

But Sanchez awkwardly pulled into second, standing, then, trying to elude the tag, fell off balance then off the bag before he was tagged out to complete a double play.

Even by today’s diminished skills and standards, this was a double play that appeared as the residual of Sanchez, yet again, failing to recognize or practice elementary, remedial common sense baseball.