Okay I am certainly not the stretching expert VZ is but let me add my 0.02 When I started BJJ I realized my guard game was bad because I didn't have enough flexibility so I set out to fix that. Every day I woke up and did dynamic stretching followed by isometric stretching before breakfast and every night I did relaxed stretching before bed. Within a little over a month I went from having my pelvis 1.5 feet off the ground to having it about 1.5 inches off the ground. I was younger and more pliable but with dedication it's certainly doable. Like a lot of things in martial arts and life most people don't want it badly enough to dedicate the grind time to it. They just want it enough to whine about it.