Can you identify what these football-related idioms mean?

Football idioms

You could consider someone who is alert and quick-thinking to be "on the ball". If you're tired after a late night, you could say, "I'm sorry, I'm not really on the ball this morning."

To cooperate. 
e.g. Come on, you need to play ball if we're going to find a solution to this problem!

To focus. 
e.g. I need to get my head in the game and work this out.

Usually used in the negative, this idiom means that two things are not really comparable.
e.g. Your painting is good but you're not exactly in the same league as Da Vinci!

To take charge or the lead in a situation. If someone tells you to "run with the ball", they want you to take initiative and make some decisions.

When rules are changed suddenly and without warning, we often say that someone is "moving the goalposts". 
e.g. We nearly reached an agreement but the deal fell apart when they moved the goalposts.

Watch carefully what is happening, to stay focused. 
e.g. We need to keep our eye on the ball and make sure nothing goes wrong.