Maybe I’m biased because it’s my event, but the 400m is the hardest race to run. In an 800 you can be in 4th or 5th around 3/4 of the race and still come back and win. If you’re in 4 place at 3/4 of the 400m, then you’re done. You can run independetly in the 800m, it doesn’t matter who’s in the lane next to you, you’re going to run a pace. In the 400m no matter how fast you are, the people around you affect you. If the guy next to you goes out too hard, then you most likely will do the same, and die in the end. If he goes out too slow then you think you’re doing fine, and come 300m you find out you’re back 4th or 5th place, and you’re done. And the 400mH is very hard, I ran 300mH in high school, and I don’t want to run it again, but one thing I noticed I could run those hurdle guys down late in the race because I was so much faster than they were. Look at Angelo Taylor, he’s a 400m runner, that runs the 400mH. When you watch him, you can see how much faster he is than everyone else in the race. Sanya Richards is a 400m runner, look at how versitile she is. Monique Henderson, ran 400, 200, 4x100, and 4x400 for UCLA, as did Michael Johnson for Baylor. Ashton Collins from the University of Texas in 2001 ran 3 800m races all year and won the Louisiana 4A state championship in the 400 and the 800. The 400m can prepare to be competitive at almost every event from 100 to 800.