We're all familiar with how DoTA can snowball in PuBs. I mean, it's 15 minutes in, and you're up by 10 kills, and everytime the enemy team sees you they run in absolute fear of feeding and being slaughtered. Early game advantage is great, because you can take that and knock down towers and keep that momentum going throughout the course of the game and WIN.
But in my games over the weekend, I saw something happen a few times. Where this overconfidence ended up being disastrous, leading to mistakes and the opportunity for the team that was loosing to make amazing comebacks.
One game that I spectated, it was 4v5, my friend was on the losing team, one player down, and at one point they were down by 10K gold. That's a TON of farm. For all intents and purposes they were way behind. So what did they do? They communicated, played smart, and took advantage of all the mistakes the other team was making in their overconfidence. In the end, they won. I think I actually stood up and cheered.
In short, when you get overconfident, you make mistakes. Confidence is always good, but thinking that you're so far ahead you can fight a 2v4, or push a lane across the river with no wards or escape route, or wandering around the enemy's jungle begging for a counter-gank...yeah not so much good in that.
Moral of the story is, play smart regardless of if you're miles ahead or way behind. Early advantage doesn't always lead to a victory, and falling behind doesn't spell certain doom. Ultimately, the best team who plays the smartest, will win.