What is the Rule of Prayer? I often hear people thank God about how their prayer being answered such as in competition. But what I'm thinking is, the winner is not absolutely the only one that prayed. I believe everybody in the competition pray and hope to win too. So, in this condition, only one person's prayer will be answered.

So, how does God decide which person's prayer to answer? Is it based on how hard s/he prayed, or how much s/he deserved it? or is it according to His will only?

If none of them pray, will the result be the same?
As a frequent competitor, I understand prayer as such following.

When I pray, I know that in whatever I do during the competition, God will be with me. As such, mishaps or any other unwanted disadvantages that may happen to me are voided. And thus I compete fairly with others with no disadvantages (such as sickness). 

However God may not answer my prayer as it may be a lesson for me to learn. 

God helps me with that, but as for the rest of the competition, it is up to me to accomplish it. God wouldn't want to intervene in order to help me win, because He wants to see me working hard and winning the competition in His will.

Competitions cannot be win by greed, as greed is sin. I pray to do my best of my abilities for all competitions.