So, I always ask the same question, but I'll put a slightly different spin on it this time.
It's the worlds. Getting into the semifinals requires us to win the last game. With a normal it's 55/45 in our favor. With a TIE it's Y/(100-Y), with Y<50.
What is the largest Y such that you'd rather normal?
I think this largely depends on on what our goals are, and who our possible opponent will be in the next round. I would kind of need more detail to give a clearer answers. However, if the goal is simply to get the semis, then obviouls you normal. If we are in this for bigger aspirations, than Again, based on the the possible opponent in the next round would determine this answer. If its two big powers, and you want any chance at all to win, then a Tie and the risk that comes with it woud be the way to go. However, its two teams fighting in the other bracket that we match up with, have poor game shape, etc, a Normal would be appropriate to get there, and still have a legit chance to win that next game.
So in a normal scenario, the largest Y would be 49, but other variables could change that. Studying the offsite forum the way I have, it looks like we have a great system of tacitcal advisors. This would be one of those situations I would want to really gain as much information as possible to know what the risks/rewards really are. I think if its one of those times that there is a collective feeling of hey, we got this far, let's go for the Gold! Then you role the dice and go with the Tie and hope your tactics get the job done.