When it comes towards visual ballistic or being into some kind of wheel signature - then the first basic lesson is to learn the wheel layout - the numbers order on the wheel witch is not the same as the table layout.
I also reckon that roulette system player would be better of master this basic skill.

Second some one should learn the basic to tell witch distance numbers has - witch might sound complected - but is very easy basic skill.
It takes two to four weeks to master the wheel as i mention above using my basic solution.

To learn the wheel at the first level has a learning curve witch is static witch make it more easy.
After master this first level some one will gain experience and all numbers will float together.
This way some one can tell neighbors from any number or distance.

First we divide the wheel into sectors of three - where the first sector include zero and has four numbers - that is the only exception.
It is a great feeling to know everything in a split second with out using any card or pen and papper.

This is clockwise direction.

0. 26 0 32 15
1. 19 4 21
2. 2 25 17
3. 34 6 27
4. 13 36 11
5. 30 8 23
6. 10 5 24
7. 16 33 1
8. 20 14 31
9. 9 22 18
10. 29 7 28
11. 12 35 3

After you learn each sector in clockwise direction you will also learn the each sectors index number from 0 to 11 so you know witch numbers belong to witch group.
Then come one other useful basic skill to learn opposite or triangular or four Angel splits.

This is the opposite sectors using the index numbers.

0-6
1-7
2-8
3-9
4-10
5-11

Using triangular or four Angel splits you just move two sectors forward in same direction.

0-3-6-9
1-4-7-10

When it comes to distance you just know after mastering opposite, triangular and four angel splits how to move forward using the numbers.
After experience you will also at this level know how to reduce or add plus or minus one pocket in each sector - that is how you can measuring the exact distance between two numbers.
Witch will become a natural reflex with in a split second.
Index numbers to get the raw distance between two outcomes - then add or reduce plus or minus one pocket.

Personally in the past i memorize one new sector each day and after i master them all in clockwise direction i memorize them anti clockwise direction.
Then when that was clear as water for me i memorize each sectors index number and memorize opposite, triangular and four angual effect.
And at last i learn how to master distance.

Today i know all numbers by heart with split second and same goes for distance.

Cheers

You can learn one sector each new day or take two days.
Have a small paper in your wallet to check that you are correct.

Then repeat the numbers when you walk or taking the buss or subway.
Before or during or after you eat.
Practice before you fall to sleep.

When you can all numbers you can try repeating them backwards getting anti clock wise direction.

 
This is to give you a visual over a bi-modal situation with numbers.
Two sectors oppisite to each other.



This is to show you a "four split" divided over the wheel like a cross.
This way you have sectors like a cross and sectors between them, total of eight octanes.