Extrema Ratio

who we are

S.G.S. E.R. one of the most advanced peronal high defense systems in the world. It is a fusion of multiple systems, techniques and strategies of combat and defense, formed in part by Street Grapple System (M ° G.porcelain) from which it adapts and explosiveness, by the FISFO system (M ° C.Joussot) for effectiveness of his techniques and warriors escrima (Guru K. godhania) for knife, stick and panantukan techniques, as well as drawing on various other systems of world-class masters and traditional martial arts.


Within the Stick program, it usually starts with an introduction to the basic methods for the use of the single stick which begin with a basic variety of grips, positions and guard positions by slowly developing a complete training for the stick.


The Knife Defense program is inspired by the Filipino martial arts which are considered to be among the most practical systems and have developed cutting edge training at a very high level.

Special Force

SGS has the characteristic of having multiple uses, so much so that it is also aimed at operators of Public Security, military, special forces and operators of close security.

VIDEO - Gallery

In this section you will find some of my videos of the various workouts. I invite you to click on the button below to view them, so that you yourself can understand the effectiveness of our system!

PHOTOS - Gallery

On this page you will find multiple photo albums that will show you my path not only martial but also of other experiences. Thanks to which I became Maestro Sandro Martinelli.


As far as I'm concerned, a very good course, especially for me who work in the field of F.P. I thank Maestro Sandro, as well as his collaborators for the professionalism and commitment they put in making me learn the various defense techniques. Thank you all

Michele Nesta

I am also very happy to have started this course. I come from another fighting style and, comparing the two, I find it much more interesting, practical and complete. You can see that below there are years and years of practice and study by Sandro and all the instructors, as well as constant commitment and dedication for us students! For this I thank you very much !!!

Anna Bortollon


Fast. practical. effective

sgs extrema ratio

Courses Timetable

Tuesday: 19:00 - 21:00

Friday: 19:00 - 21:00

Come and try a free lesson