Solitaire simulator for finding the best strategy: Current record is 8.590%

Per [1] (found via wikipedia) 35% is possible!

[1] https://web.archive.org/web/20210924183919/https://www.aaai....

Isn't 8.5% low?

My mom didn't use the computer much except she did play solitaire on her Windows laptop all the time. She had over a 2000 game win streak until she got dementia and stopped using the computer altogether.

What is 8.590% of what?