Don't you just love it when your in the middle of a trick and the pen seems to lock into where you need it and it goes so smooth. Man i was enjoying it!

Anyway, i was just wondering what does the whole sonic 12,23 or something like that stands for. I don't understand. Someone please explain.

Sonic 12-23 means

The pen travels from 12 (between index and middle) to 23 (between middle and ring)

T=Thumb
1=Index Finger
2=Middle Finger
3=Ring Finger
4=Pinky Finger

For the record a normal Sonic does not travel from 12-23.

The numbers correspond to the fingers used in the trick, as xz64 pointed out.

A lot of tricks can be described just based on the starting position...
Sonic 23: the basic Sonic that starts in between the Middle and Ring fingers (23), and ends in between the Index and Middle (12)

For further clarification you can give the beginning and ending positions...
Sonic 23-12: same thing as just saying Sonic 23. It starts in 23 and moves to 12.

If a trick goes against the basic positions you can also give the starting and ending positions...
Sonic 34-12: starts in 34 and moves to 12. It skips a slot instead of ending in between the Middle and Ring fingers (23).

ah thanks guys! i understand now.

so just to make sure i understand
for sonic reverse U'd say sonic reverse 12-23-34 or something

Sonic Reverse 12-23 goes from between the Index and Middle fingers down a slot, it ends between the Middle and Ring fingers.

Sonic Reverse 23-34 goes from between the Middle and Ring fingers down a slot, it ends between the Ring and Pinky fingers.