The speaker thinks DeepThink, o3 Pro, and Grok 4 Heavy use parallel thinking by running about 10 variations of the same model and using a judge model to select the best result.

“yeah i think it's reasonably known that deepthink and o3 pro and grok4 heavy are all like parallel thinking right like they all just run like 10 different variations of the same model and then they have a judge model choose the best result i yeah i'm not sure like i think that the existence proof that there's been something qualitatively different”