Perfecting a technique ensures that you’ll be able to execute it perfectly from a distinct starting point.
But what if you never find yourself at that starting location?
Perfecting a system ensures that you’ll be able to execute a move from every starting point possible.
As you become proficient in a technique and begin to practice it; you learn about the counters to the technique and how to prevent them; the set-ups, the angles and preconditions required to execute the technique; and the principles which apply to the technique, and to your opponents reaction.
The implementation of these counters, set-ups, angels, preconditions and principles is the systems based approach to learning Jiu-Jitsu.
A Jiu-Jitsu system endeavours to define all possible scenarios within the system.
Mastering a system maximises your chances of submitting you opponent once you have them within in.
For example, you can have the best swinging armbar from guard on the planet, but if your opponent would rather be triangled than let you cross his arm over your centre-line, you better have a good triangle set-up too.
Having an incredible armbar is worth nothing compared to having an incredible guard which includes a great armbar.
It took me a while to realise this, so for those of you just starting out; apply a systems based approach. Don’t just ask your instructor how to execute a technique; ask how, why, when, and when it doesn’t apply.