I've been looking for a decent description, and well, I'm still looking, but this statement was excerpted from a longer write-up by Tim Waid:

Thanks for your reply. I already understand the principal of the tri-V formula, What I was hoping to find out was why tri? Since no one here can come up with a logical answer, I'll give it a "stab" What I could only think of is there should be three reactions to every action. Example: tri-v works off of triangles as does most filipino Martial arts, This already knew from my experiance in Kuntao Dumpag, and training in the Inosanto-Lacosta blend, but in the tri-v formula you have one angle with your footwork,the second angle would be the angle of your slash, and the third angle would be your body structure,the angle you put your body to avoid the attack. Put together you have three defenses or "counter offenses" to each attack.

how about 3 strikes right before he tries to do one strike. This is advanced stuff though and not of any use to someone who hasn't mastered the basic 12 methods.

As Jason stated, the Tri-V formula cannot be learned without training the related basics. The pieces of the puzzle just won't mean anything without that understanding. However, the TRi-V Formula is actually a condensed / accelerated lesson plan for the Pekiti Tirsia System. Grand Tuhon designed it in order to get people functional and fighting sooner. One example of this is how he is introducing the fundamentals of the contradas right away to new students. This material used to be reserved for later in a student's training. Tuhon enjoys puns, double meanings and word play, so he has offered several meanings for the the term tri-v. One of which was the simple pleasure of recognizing that there are 3 V's in the shape of a triangle. Anyway, there is obviously the very significant triangle reference. As you all know, and some of you have mentioned, the triangle serves as a template or guide for how we apply our footwork, our strikes, takedowns, targeting, etc. Sometimes the triangles are only referred to as a "V" or expressed as the forward triangle, reverse triangle, closed top or open top. Tri or 3 is a significant number in and of itself which also relates to how many strikes we use to engage, the phases of an attack as well as a host of other references. These are all parts of it as they are all parts of Pekiti Tirsia. I believe in old faxes or emails that Tuhon sent to me in the late 90's, Tuhon originally referred to it as Tri-Vertical, but soon thereafter only referred to it as Tri-V Formula. As far as the lesson plan is concerned, the Tri V formula has 3 major domains which are summarized categories from the overall PTK system and so the name. Ultimately the formula is not just a collection of drills or techniques, it is also the training method and your ability to inquire, learn, understand and apply that knowledge. Your best option to learn is always to study directly and often with Tuhon himself, then the real value of the training will be apparent. Otherwise, your local Pekiti Tirsia Kali instructor should be able to guide you. I hope that helps. Best regards,