There is nothing on that website that says that there are 5 semi-finalists. To the contrary, it says this:
"Registration Deadline:
Qualifying Submission and Competitive Agreement Deadline, Semi-Finalist teams announced
September 8, 2020"
It also says this:
"August 31, 2020 Registration Deadline; Qualifying Submission and Competitor Agreement Deadline, Semi-Finalist Teams Announced
September 15,2020 Finalist Teams Announced (up to 20 teams)
"?Semi-Finalist Round: ?The first round will require the top 200 registered teams to check their solutions against a blinded proficiency test."
One more time. Tell us EXACTLY where you learned that "Out of 800 there are 5 left" and include a link or admit that you made it up.
I'm not questioning the truth of what the Company is saying. I just don't understand it. Quit whining and explain it.