Something interesting is happening with the guillotine choke.
In The Ultimate Fighter-era of MMA, it was a powerful weapon used at the highest levels of unarmed combat. As defense to the choke improved, however, it's effectiveness became badly compromised. By 2011, according to Fight Metric, guillotine choke attempts in the UFC were only successful 11 percent of the time they were tried.
However, changes were being made long before 2011, innovations that only now seem to be bearing fruit. While the conventional guillotine was in decline, adaptations to it in the form of grip, position, squeeze and pressure points were blossoming.