This is in the wrong section. But I'll answer anyway.
You are making this waaaaaayy too hard.
Call this URL: http://www.fivb.org/Vis/Public/JS/Beach/TechPlayRank.aspx?Gender=1&id=BTechPlayW&Date=20180326
The "Date" field here, is 4 digits year + 2 digits month + 2 digits day.
Valid Gender is 0, or 1. The page you linked to was using 1, as in the link.
The "id" field changes the source code of the JS file returned, to specify which element the data should be loaded into. (I believe).
That is the data that the page is loading (as you correctly guessed) via AJAX.
Now, the data that you are getting pulled in is actually a JS file. So, have fun parsing that.
But all of the data is there, and you have a more efficient way of scraping the data.
(I'm assuming that you DO have permission to be scraping this data, and if not, you should probably make sure you do.)
99.9% of the time, when you face a difficult task, there's an easier way to be doing it.
Let me know what you think of the solution.