Detailed Instructions: Given a premise, an initial context, an original ending, and a new ending, the task is to generate the counterfactual context that is aligned with the new ending. Each instance consists of a five-sentence story. The premise is the first sentence of a story, and the second sentence, which is the initial context, provides more information about the story's context. The original ending is the last three sentences of the story. Also, you are given a new ending that can provide the new story with the same premise. You should write a counterfactual context to explain the small differences between the original and new endings. More specifically, a story context contains the general plot of the story. And a counterfactual context is a slight modification to the initial context. To sum up, you should write the second sentence of a story based on the premise(first sentence) and the new ending(last three sentences) of the story.
Problem:Premise: Kevin Durant used to play for the Oklahoma City Thunder. 
 Initial Context: He was the team's best player. 
 Original Ending: His team lost to Golden State in the NBA playoffs. Once free agency began, he decided to sing with a new team. He left the Thunder and signed with Golden State. 
 New ending: The next year, his team lost to Golden State in the NBA playoffs. Once free agency began, he decided to sign with a new team. He left the Thunder and signed with Golden State. 
Solution:
He was the team's best player in their playoff series win over Golden State.