To figure out which year of high school academics is the most important, it helps to think of high school as a marathon.
In order to win a marathon, of course you have to run the whole time—if you stop running, then lots of other people will pass you. But because you're human, when you're running a marathon, you can't really run at the same speed the whole timed. Instead, you learn to pace yourself early on, and then really bust out your best sprint when it counts—at the finish line.
So which part of high school is that all-out sprinting finish line? Read on for our answer.