The OP is barely intelligible. But OBS comes into it because the issue is whether touching the fielder's foot is OBS. If you rule it is, then the runner is not out. If you rule that it isn't, and the runner is not touching the base when tagged, then he's out.

Didn't the OP state F4's foot was was on the bag? Which tells me there was access to the base. How is this OBS?

Maybe I've been reading this wrong!

Here's the OP. As far as I can make out, runner's foot is on F4's foot, which is on the bag. So the runner was blocked off the bag. So OBS is possible.

I'm not saying it's OBS: you'd have to make that ruling based on what happened.

I think it is great you tried to use a rule to justify your opinion.

A rational discussion is dependant upon using ALL the rules that provide ALL the appropriate information to make a wise decision. I used all the rules to make my decision.

You only used 1 rule. If you deleberately ignore the others then you are making a decision first then looking for a rule to agree with you. You should be first looking for all the rules THEN make a decision.

You will learn that the criteria you judge to rule obstruction on a baserunner beween the bases is different than a player blocking a base without the ball. The definition is too general to apply to specifics.