Open Front Split may not be as pretty as a Squared Front Split or a Side Split, but it sure gets work done.
Called by another name a Turned Out Front Split, is an important foundation for many disciplines such as Dance, Martial Arts, and Figure Skating. Various techniques in these and other sports and disciplines can benefit greatly from this Split.
However, an Open Front Split is really two splits. One resembling more of a Side Split and the other more of a True (Squared) Front Split.

Can you Spot the difference?
1. For example a dancer performing a penche actually finds herself in a something resembling a True Front Split, with a rear leg turned out.
2. While a martial artist is in a Side Split with one leg turned in.
1 vs 2
So what difference does this make? Well, in the two cases stated above different muscles are lengthened. Think about it. Having to turn a hip out vs having to turn the hip in. Further more, not only different muscles are lengthened, different muscles are contracted to move into and keep the position.
A dancer is lengthening the medial rotators (Adductors, Pectineus, TFL) and contracting the lateral rotators (Gluteus Maximus, Deep Six) . While a martial artist is lengthening lateral rotator of the hip (In the given position, Quadratus Femoris is under most stretch) and tensing medial rotators (Gluteus Medius and Minimus and Tensor Fascia Latae).
So while the two Open Front Splits look the same, they are not. This is evident by the fact that a Dancer’s side kick looking like Penche and Martial Artist Penche Looking Like a Side Kick on first attempt.
So while a True Front Split and Side Split look cool. It’s often the Open Front Split that get’s the work done. Depending on what you are doing of course…

Paul IDAUTHOR: Paul Zaichik is the founder of the Elastic Steel method of Athletic conditioning. With an interest in Martial Arts from early childhood Paul during his Martial Art training realized that many advanced students could barely kick to the head level. He had begun to experiment in this area. As a result Paul transformed many Eastern European Stretching and Gymnastic techniques to meet the needs of the modern martial artists. More and more students were practicing Paul’s techniques, acquiring great strength and flexibility in return. As a certified Exercise and Nutrition instructor Paul has been able to develop over the years many effective techniques that became to be known as ElasticSteel.