D'arce choke/Brabo choke

Paulo Thiago D'Arce Chokes Mike Swick [UFC 109] .gif from mma-core.com

To keep things simple for me, here's a quote from Train Fight Win's pitch for their D'arce choke technique video:

The Darce Choke (also known as the Brabo choke) is one of the most devastating chokes in any grappling art form. It utilizes a squeeze of both carotid arteries to block the blood flow to the brain, rendering the victim completely unconscious in mere seconds. This choke has been sweeping the grappling and MMA world by storm, and is largely popular because it can be fully applied without sacrificing much position. Even a beginner can use this choke with devastating results if they set up the submission correctly. In this video set, you will learn over 20 setups for this submission from most every position you can think of.

During the course of a fight, both competitors become sweaty and slippery, making some submissions (such as armbars from the bottom) very difficult to complete. In many of these cases, your best option is to choke your opponent. Chokes have a very high success rate when applied correctly, and even if they are escaped- they leave your opponent weakened and tired. The Darce Choke is an extremely powerful choke that has more setups than virtually any other choke without the gi. [...]

In addition, here is this very brief video explanation.  Also, check out these vids:  

• Darce Choke to Triangle Choke
• X-Guard Sweep to D'arce Choke  
• Butterfly Guard - Arm Drag to D'arce Choke  
• 10th Planet Jiu Jitsu: Darce Choke 
• Brandon Quick (10th Planet) demonstrates Baby Wipe Pass to Darce 
• D'arce Gator Roll 
• Darce Choke from a scarf hold reversal 
• Jason "Mayhem" Miller - "Canadian Darce Choke"  
• BJJ Brabo Choke Part 1, Part 2, Part 3, Part 4, and Part 5.
• Darce counter and recounter (10th Planet) (major echo) 
• Darce to Darce to Darce 
• Darce Defense -The Heat  

Practice, practice, practice.