Umpire for 42 years...

[Dakota]

Originally Posted by Agreen_14

If there was a play at 3rd with the ball coming in from the outfield, he would protect the base like a goal to try to prevent you from getting to the bag. The ball was clearly not in his hands yet and he's down on both knees blocking the bag so that he could catch the ball and make a tag. The runners only option was to either run around him, slide through him, or jump over him... This is OBS right? If not, then I definitely need to reread the book.

It is probably obstruction... "probably" because blocking the base is not obstruction - impeding the progress of the runner is. Whether or not this was obstruction would depend on where the runner was and what he did.