Here are the Top 9 benefits for Yoga for grapplers:
- Lesser injuries.
- Better breathing [huge!]
- Better use of energy, so you can spar more.
- Moving smoother and quicker.
- Increased flexibility, of course.
- More powerful submissions and being able to hold them much longer.
- Improved balance,base and control from top.
- Your core will get much stronger, and this will help all aspects of your game.
- The number one thing for me is the mental calmness (Keeping Cool) you get from yoga, which is paramount and crucial in a big tournament.
This video is from a BJJ guy called Sebastian Broshce who owns a website I am a member of called Yoga for BJJ. I suggest you check it out if you need some follow along stretching routines. There is a paid version and a free version of his site, but even on the free version you can get a ton of great info.
And here is a Flexibility for BJJ video by Ryan Hall: