Fable 5 vs. GPT-5.6 Sol: Does the /goal Feature Actually Help?

Fable 5 vs. GPT-5.6 Sol on an NP-Hard Problem: Does /goal help?

I tested Claude Fable 5 and GPT-5.6 Sol on a tough NP-hard optimization problem, comparing their performance with and without the native /goal mode. Fable 5 proved to be an absolute beast, delivering the best overall solutions with incredible consistency. Surprisingly, the /goal feature wasn't a magic 'try harder' switch; while it won more individual trials, it actually worsened the average performance by occasionally amplifying bad strategies.

"The result I would put in the headline is not that goal helps or hurts. It is that a persistence feature can win most individual trials while making observed average performance worse."