Probability factors?

Hello



I am having a hard time understanding which factors should be taken into account and which ones should not be taken into account when calculating probability.



I have the following situation:



Last night I played FIFA12 on xbox live against an unknown opponent. He challenged me to a rematch after the match was over.



I would like to calculate the chance I would have had of winning if I would have said "yes" to the rematch.

However, upon trying to calculate the chance (using Bayes' theory for example), I quickly gathered countless factors such as:

• previous personal win/loss ratio


• the fact he first scored a goal in the first 10 minutes of the first half


• the fact I scored two goals the last 20 minutes of the second half


• his predictability


• my predictability


• my fatigue at that hour; mentally as well as phyiscally


• the knowledge the opponent has about my strategy after having played a match with me


• how tired my opponent is


• the opponent's fatigue; mentally as well as physically


• if he is a night person or not

I keep thinking of factors such as these and I am not sure which ones would be valid factors for probability calculation. I am getting lost.



Does anyone have an idea on this?



Thank you