Even your link doesn't really help me understand how you can guarantee 100% answered prayer.
And you still haven't told us how you can confirm that the prayer is the actual cause and nothing else.
Timing. You ask, God answers, then at that moment, He delivers.
Action, response, reaction.....it's all very scientific.
I'll give you another example. A true story.
A person called by God is sent on a mission.
In a blinding snowstorm he is stopped by the edge of a river.
He stands and waits for the next step, becasue he knows
God sent him on this quest.
Out of the blizzard a man arrives in a boat to pick him
up and help him cross the river.
The boat man relates that he was awoken in the middle of the
night and "told" he was needed at the river. Going to the river
he finds a row-boat used for helping people cross the water.
He heads out in the storm to find the person he is supposed to help.
He arrives on the opposite shore and finds the man on the mission.
All random chance in the middle of the night?