I was watching the result of IMO 2014 where I found that China was on Top and USA, Russia were following China. This is not the exceptional case, you can pick the results of each IMO in some of the previous years and you will find that these countries have ranked in that order from a long time.
My question is what makes these countries so great in this field and What's the reason behind poor performance of globally known countries such as India, Brazil.
I shall be thankful if you guys compare the programs running for this purpose in all of the above countries and any advantage of being an IMO participant in high scoring and low scoring countries a participant have.