In this issue we investigate the U.S. Open to try to explain why it's been so long that Americans have the U.S. Open champs. What does the data reveal?

1. 9/12/11

2. The U.S. Open This table shows country of origin for each of the men’s singles champions from 1970 to 2010. The U.S. winners are highlighted in red.

3. The U.S. Open Let’s change this to numerical data by assigning a U.S. winner to1 and a non-U.S. winner to -1. This is the revised table.

4. The U.S. Open Create a bar graph of the data in the table. You’ll see that there seems to be a periodic trend in the data for U.S. winner.

5. The U.S. Open Let’s smooth out the data this way: If a U.S. winner is not part of a group of 2 or more, assign its value to -1. Here is the revised graph. Now you can see the periodic nature of the U.S. winning streaks.

6. The U.S. Open We can overlay a sinusoidal curve over this graph to more clearly see the periodic nature of the data set. Notice that these sinusoidal curves have different widths.

7. The U.S. Open The period of the first sine curve is 15 years. The period of the second curve is 12 years. And the period of the third curve is 9 years. The average period is 12 years.

8. The U.S. Open We can now construct a periodic model from the data set. A standard sine function has a period of 2π.

9. The U.S. Open To change the period to 1, multiply the x by 2π. This function can be used as the basis for creating a function of period 12, representing the average cycle for U.S. dominance in tennis at the U.S. Open.

10. The U.S. Open This function has a period of 12. We now just need to adjust it so that it is in sync with the periodic nature of our data set.

11. The U.S. Open This is the function that models the data set, and according to the graph, the U.S. will once again have dominance at the U.S. Open around 2016, and then once again in 2028.

12. The U.S. Open Buy why would American dominance at the U.S. Open be periodic? When there is a dominant player (or players) they have a much higher probability of winning and during their prime, they will have several championships.

13. The U.S. Open Here is the graph again, this time with actual winners identified. Jimmy Connors John McEnroe Andre Agassi Pete Sampras Andy Roddick Pete Sampras

14. The U.S. Open If the trend holds up, then there is likely to be one or more American players who will become dominant over the next few years. Jimmy Connors John McEnroe Andre Agassi Pete Sampras Andy Roddick Pete Sampras

15. The U.S. Open As a final activity, here is the data for the women’s singles champions over the same period. Perform the same kind of analysis we did with the men’s data. What can you conclude?