News

New Instances and Scoring System Released

We have expanded the benchmark set to 250 planar triangulation instances. Along with the original 201 small and medium instances, 49 large instances have now been added in response to community feedback.

We have also released the updated scoring system, which will differ slightly from previous years to better reward both exact methods on smaller instances and scalable heuristics on larger ones.

You can find all resources on the project page. We are looking forward to your submissions.

Dear participants,

We have received some quick and constructive feedback - thank you very much!

A quick heads up: There will be a number of additional, considerably larger benchmarks. You can expect these to be released within the next week, together with some more detailed description of the scoring system.

Thank you all, and keep up the good work!

The Challenge organizing team: Oswin Aichholzer, Josef Dorfer, Sándor Fekete, Phillip Keldenich, Dominik Krupke, Stefan Schirra

We just published a few example instances for the CG Challenge 2026. You can find it under "Downloads". It contains a few instances of varying difficulty, including some for which only the parallel flip distances is required. At this point, we are still open for suggestions regarding the final benchmark …

Discord Server we have set up a Discord server for the CG Challenges, where you can casually ask any questions about it, as well as connect with other participants. It will probably take some time to get populated, but at least the organizers will be listening :) https://discord.gg/3FXC6xzzWe