Cortazar begins the narrative with the plot concerning the motorcycle accident rather than the one about the manhunt. why it's this choice ann effective way to structure the story?

He starts the narrative with the plot concerning the motorcycle accident rather than the one about the manhunt to establish later on the struggle that the main character faces between the two worlds. It also helps the reader to understand the message/theme of the story as to what is happening in the surrounding environment as well as the thoughts of the main character.

“The Night Face Up”
Real World or Aztec World

I hope this helps, Regards.