call the shots (or tune) take the initiative in deciding how something should be done; be in control. informal

☞ Call the shots was originally an American phrase, first recorded in the 1960s in the context of dice gambling. Call the tune comes from the saying he who pays the piper calls the tune, which dates from the late 19th century.

2014New Statesman In the event of a future financial crisis, the UK chancellor calls the shots and can direct the Bank of England's governor to take specific action to restore financial stability.