Merck (NYSE:MRK) has one of the largest dividends in health care, but does that make it one of the sector's top dividend stocks? 

In this video, Motley Fool Healthcare analyst David Williamson will be grading well known dividend stocks using a World Cup inspired grading system: a yellow card is a warning for investors, a red card is an ejection, and a "goal" happens if the stock looks like a winner. 

Watch and find out the current strengths and weaknesses of Merck and if it should be ejected by investors.