Ashtanga has always deeply fascinated me, and during the last few years I've come to appreciate more and more the fact that this practice is at once both the postures and the transitions between them --- it is equal parts movement and stillness.
The static postures are themselves dynamic, and there is a fixed and steady quality to the transitions — let's not belabor that any further.
In Ashtanga, the movements into and out of the poses are utterly prescribed, that is, predetermined and established --- the breath-body movement, the vinyasa, is established to such a degree that in guided classes it is counted off in Sanskrit.
Guruji used the Sanskrit number for certain positions as short-hand for the position itself, such as when he'd shout, "Chatwari --- chatwari!" which became shorthand for chaturanga dandasana.
Ashtanga yoga's fundamental cultural hybridization is explicit in the guided classes — while the vinyasa count is in Sanskrit, the breath count is in English, and many of the variations of the Sanskrit poses have Roman alphabet names, such as janu sirsasana A, marichyasana A, etc, etc.
The vinyasa count is a dynamic pattern marked by the measured repetition of inhale and exhale. To practice Ashtanga effectively, it is contingent upon us to perform this cycle imperfectly, as it is the perpetual return to attending to the breath (and bandhas) that makes Ashtanga a practice. The breath cycle is only made alive and meaningful through its disruption — therefore it is an essential part of the vinyasa practice to lose the breath count.
This is also how the bandhas function. Both vinyasa and bandhas are paradoxically dynamic processes, as well as fixed states.
I lose the breath count when my mind wanders ("What's for breakfast?" "He's cute," "What's that string on my rug?" etc, etc), and it is this interruption or gap in concentration that lets me practice returning to concentration.
Concentration is not just a 'static' state, it's like balancing on your hands: the illusion of stability is created by course corrections so minute as to be imperceptible. As Mozart said, it's not the notes, it's the silence between.
As such I don't much care for the idea that this practice can be done "perfectly" — or at least, I don't care for the focus on the vinyasa without a corresponding reminder of what the vinyasa is for. To chase perfect vinyasa is akin to chasing the perfect 10 at the Olympics, and renders Ashtanga yoga a treasure hunt, or worse yet, some combination dial on a safe --- "If I can only dial in these poses perfectly, in this order, there is a wonderful prize waiting for me."
Mysore practice is also not a memory test — its aim is not to establish the quality, performance, or reliability of your recall. This is a practice of imprinting, initiated by samastithi at the beginning and sealed at the end by baddha padmasana (yoga mudra, the imprint of connection, stilling, joining, etc, etc). The breath-body movement and looking places gradually and gently hone the craft of attentiveness, concentration and absorption.
It is more important to orient our practices to the purpose of the vinyasas as well as the bandhas, and that is as a means to express and experience, and become saturated in, Patanjali yoga, whether that means stilling the waves of the mind and 'uncovering your lamp,' experiencing 'aloneness,' or dissolving the threads of experience, etc etc.
I am not suggesting that the breath-count and bandhas do not matter. On the contrary, they should be vigorously, heroically tended to. Over time the interruptions might occur with less frequency, but it is important to remember that 'perfectly' performed vinyasa as well as the bandhas are a means to an end. They are a structure, a shape, and a container for our efforts.
Jason owns and directs Portland Ashtanga Yoga.