Re: Buster Posey injured
Put me in the camp that says position players should not be allowed to obstruct the bag, period, with or without the ball. That goes for catchers just the same as it does infielders who drop a knee. Baseball is not, nor should be, a contact sport. Blocking the bag simply demands the runner to induce contact -- contact nobody is prepared for.
I say if a runner is not given a clear path, he should be safe automatically. And if a runner initiates contact despite having a clear path, he's should be out automatically. That would eliminate so many injuries at home plate and when turning the double play. I know those events are currently part of the, but I don't think they're necessary nor add value on balance.
Games are won on run differential -- scoring more than your opponent. Runs are runs, scored or prevented they all count the same. Worry about scoring more and allowing fewer, not which positions contribute to which side of the equation or how "consistent" you are at your current level of performance.