For every task there is going to be multiple ways to get from the beginning to the end. If you want to get strong then you have to lift weights - but there are countless methods and protocols dedicated to getting stronger. If you want to get flexible then you have to stretch - but there are countless methods and protocols dedicated to enhancing your flexibility. If you want to enhance your cardiovascular capacity then you have to do cardio - but once again there are countless methods and protocols dedicated to increasing your aerobic capacity. So, it comes as no surprise, that if you want to increase your mobility there are going to be countless (and oftentimes conflicting) methods to do just that.
In the case of enhancing an athlete's mobility I have always taken a two-prong approach: foam rolling to release the underlying tissue and mobility drills to stabilize and realign the structure. Doing one or the other works quite well but the combination of the two, done consistently, seems to pay off for our athletes. It's not easy, and it's often an uncomfortable process, but like most things that are worthwhile there has to be a price to be paid. We've had people come into train that are pretty beaten up by life (and by unsafe training practices) that are now moving pain free. These same people were under doctors care and on steroids and anti-inflammatory drugs; but have learned that the most powerful drug out there is listening to your body and learning how to mitigate the abuse that life and training dish out.
Check out this article from the Breaking Muscle website entitled "Foam Rollers Don't Work: Understanding Myofascial Release". It gives some great information on the science behind how tissue is composed and how it responds to work and injury. While it refutes the benefit of Foam Rolling, which I have personally used successfully for many years with athletes, it does point out some alternatives to explore in order to get the most from your body.
NOTE: check out the picture above one more time. That's John Kalil and he is an RKC (Russian Kettlebell Certified Instructor) who teaches eight to ten classes a week, and at least that many private clients. He is 73 years young and moves better than most people half of his age. His secret? Daily training with Russian Kettlebells, mobility drills... and foam rolling!