Why this article is different... foam roller (love this for massage AND oversplit), the scissors stretch...I have never seen before, the active leg stretch I thought about myself when seeing a tutorial on doing aerial cartwheels.
Beginner Center Split: One Knee Bent... Once comfortable with previous stretch (knees bent) try with only one leg bent! Your body should form a straight line from the bent knee to the toe of the straight leg. Point your toes - it will help you to practice good form now in your stretching. Switch which leg is straight. Do each side for 30-60 seconds.