League-of-legends – What does commentator say when baron kills your entire team

This is a very broad question . You're not looking for a time or a level, but rather a one condition: You know where enough of the enemy team is that you're sure your team won't get jumped while killing Baron.

Typically, such awareness comes in the form of just having killed a few of the opponents. Then, you know exactly where they are: waiting to respawn.

Outside of that, ward placement and other general strategies for gaining map awareness can give you an idea of where everyone is. If you see three opponents on the bot lane countering a minion advancement, you can be pretty comfortable with the idea of going for a Baron kill even when you're not sure where the other two opponents are.

Keep in mind, however, that on top of knowing where they are, you want to be sure they can't get to you in enough time. As your team gets higher in level, they will need less time to down Baron. You'll want lots of time in earlier levels and possibly as short as 10-15 seconds at higher levels.

When you are losing team fights, you need to defend (That's your first priority). With that being said, stick together as a team and prioritize your towers, you want to keep a strong line of defense, so don't try and save the farthest tower if the other two lanes are down to the inhibitors. It seems dumb to let a tower die, but if your team stays back and farms up the minions while holding a decent enough defense, you will be surprised how much the farm will help your team catch up, and hopefully win a team fight.