https://en.wikipedia.org/wiki/Endgame_tablebase
This market resolves yes when a complete 8 man tablebase is finished and released. This tablebase must include every position, not just "nontrivial" positions. In the event something is released but it takes time to verify, this market resolves to the year in which the complete version of the tablebase was accessible by a member of the public. It's okay if the tablebase requires a fee or subscription to access, as long as any member of the public could theoretically access it and it is verified to be complete. It is unlikely that I bet on this market, and if I do I will sell all my shares before resolving the market
1,000No, although I doubt that would exist anyway. A tablebase must be an exhaustive database of results from all 8-man endgame positions. If a perfect chess engine is somehow used to create this it would count (as long as the tablebase is actually complete and correct in every position), but the entire database must be constructed