Definition
To cooperate or agree to work with someone, often after initial reluctance or disagreement.
（与…）合作，配合
After many negotiations, they finally agreed to play ball and collaborate on the project.
经过多次谈判，他们终于同意合作并共同完成这个项目。
It will be difficult to push through these reforms if the government doesn't play ball.
如果政府不配合，这些改革将很难推行。
They initially refused to participate but eventually agreed to play ball.
他们最初拒绝参与，但最终同意合作。