If you come off the base at all and get tagged, you are out. pretty simple. I don't buy the argument that for 150 years we couldn't have seen you were out so you shouldn't be now. The same argument can be made about the strike-zone. If we are going to allow review, then make the call whatever the review clearly showed. If you don't like the rule, which we are now better able to enforce than we were before, change the rule. Advocate for the rule that a runner is safe if he touches any base before he is tagged and makes no effort to advance to another base, if that is the rule you want. I'm fine with the current rules and fine with the corner-cases of NFL-like review of inches. If you are worried about frivolous challenges wasting time and just letting ALL close calls stand, I'd also be fine with putting the decision of whether or not to review in the hands of any umpire not named Angel Hernandez.