The speaker says the best agent incorporated search-algorithm improvements, a context-management system, and a complete prompt rewrite.

“There's a lot of changes, but to boil it down, there are search algorithm improvement,”

“there are better...”

“Context management system and there is a complete rewrite of all the prompts and more interestingly we find the design mechanisms prevent itself from reward hacking like the outer loop trying to prevent the inner loop from cheating the benchmark.”