To increase flexibility you have to hold the stretch for at least 90 seconds steady - no bouncing, no taking a break - 90 consecutive seconds a day. Do your right split as far as you can, and hold it. Watch TV or read a book to distract yourself. It will be a slow process, and it's not going to be comfortable. all you can do is do it and be patient. I can do oversplits on both sides, so I know what I'm talking about. :)