Unfortunately it became notoriously rage inducing among gamers due to Sega taking the unusual step of refusing to let anyone know what the actual button combinations for moves were and instead telling them to work it out, which no-one did.
After much searching of the internet in vain, I decided to work it out and so for you now, an internet exclusive as you will not find this information anywhere else.
Circle, X, Square, Square - Basic Pin
Once it's locked in you'll have to hold it for 24 seconds using the shoulder buttons
Circle, X, Triangle, Triangle, Triangle - Advanced Pin
Your hold bar will start from a more advanced position, making it easier to hold and also seemingly easier to pick up a score.
Triangle, Triangle - Rolling Choke
The simplest choke and most difficult to hold with the shoulder buttons.
Triangle, Circle, Circle - Rear Choke
Hold it for 10 seconds and you've won
Triangle, Circle, X, X - Arm-lock
10 second rule again
Triangle, Circle, Square, Square, Square - Cover-lock
The most advanced submission and possible to score with.
X, X - Leg Sweep
You'll kick their legs out from under them. Shoulder buttons do not work here, you need to defend the throw with the pad buttons.
X, Square, Square, - Push
You push them backwards over your outstretched leg. Again, bash the pad buttons to make the move more effective.
X, Square, Triangle, Triangle - Pull Sweep
Pull them towards you while kicking out their legs. Use the pad buttons
Square, Square - Hip-toss
Roll them over your hip, landing on their back. Pad buttons
Square, X, X - Roll-flip
Grab, roll backwards and flip them onto their back. Very effective for scoring and use the pad.