"David Karchmer is without a doubt, the best referee in the grappling world today. There is not a referee on the planet who is more professional, detailed, and prideful in their work.  While beginning to prepare the inaugural Rickson Gracie Cup, acquiring the "Silverfox" was first on my list! He prepared a ref staff, trained them for the new rules and kept things running smoothly over the two day event.  In the future, I will not hesitate to work with Dave.   If you plan on hosting a BJJ or grappling event and want to have the highest level of officiating, hire the 'Silverfox' "!
                                                                                                                                                                                                    - Eddie Fyvie, promoter Rickson Gracie Cup East Coast

"David Karchmer was an invaluable part of FIVE Grappling and our ability to provide industry leading customer service at our events. David was the lead consultant for the formulation of our rule set and most importantly, his professionalism and attention to detail were at the absolute highest level. His deep and intimate knowledge of the rules and point system in Brazilian Jiu Jitsu are unsurpassed. Additionally, David was also able to recruit the best refereeing talent due to his many years of connections and stellar reputation in the industry. I recommend David 100% to anyone that is considering working with him." 
                                                                                                                                                                                                      - Dayan Henson, Former CEO, FIVE GI.NO GI GRAPPLING 

"With his calm yet commanding presence, having David Karchmer leading your referee team is like having a 4-star general on the mats."
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                                                                                                                                                                                                      - Alberto Marchetti, CEO Rollmore.com Group, Former Head Referee for                                                                                                                                                                                                GRAPPLERS QUEST, Founder ROLLMORE SUPERCOMP TOURNAMENTS

"I first met David Karchmer at dinner with a mutual friend following my first FIVE Grappling tournament in California.  Through my conversation with David, I was thoroughly impressed at how he was able to understand grappling rules beyond the obvious.   He understood their reasons for being, the nuances of their application, even their flaws and shortcomings.  I was so persuaded by his views, I asked David to be our resident 'Rules Expert'.  He’s since written many articles on the subject of rules and refereeing that have been published in Jiu-Jitsu Magazine."   
                                                                                                                                                                                       - Mike Velez, Publisher/Editor-in-Chief, JIU-JITSU MAGAZINE