Sunday, December 27, 2015

2015 USTA League team winning scenario percentages - Interesting tennis league stats

A question was asked on Talk Tennis about how often a team wins a match by winning the three doubles courts while losing the two singles courts.  I calculated the answer to that (5.9%), but that naturally caused me to look at all the other scenarios a team could win a match with.

For this analysis, I looked at all 2015 championship year 18 & over and 40 & over matches that were a 2 singles and 3 doubles.

To start, there are three scores a team can win a 2 singles / 3 doubles match with: 5-0, 4-1, and 3-2.   There is only one way to win 5-0, five ways to win 4-1, and ten ways to win 3-2.

Here is a chart showing the percentage each one occurred along with what would be expected based on the number of permutations for each score.


Somewhat surprisingly, teams winning 5-0 occurs a lot more often than expected.  I've done double checking of the data and I am not including defaults or retirements, so I think it is accurate.  Even 4-1 occurs more often than expected while a 3-2 score occurs most often, but less than expected.

But what about each specific winning scenario?  There are 16 of these, and the chart below shows how often each one occurs.


The x-axis is showing the courts won in the order singles 1 and 2, then doubles 1 thru 3, e.g. 11110 is winning all courts but 3rd court doubles.

Since there are 16 potential results, if each one was equally likely, you'd expect each to be at 6.25%, but we see winning all the courts is again a lot higher, and the 5 4-1 scenarios are all over, and then all of the 3-2 scenarios are under.

I'm not sure exactly what this tells us other than close 3-2 matches are less common than you'd expect.

What do you think?  Is this consistent with what you see in your league?