Table Of Contents:
Intro
1) What is a Side deck?
2)What do you Need for a Proper Side Deck?
3) How to Build a Competitive Side Deck?
4)Examples of Side Decks
5) Why is Important to Use a Side Deck in Competitive Duels?
6)Different Types of Siding
7)Hybrid deck.

Intro
Siding in Yugioh is very important for not only on large stages such as YCS and World Championships, but also academy testing results to get into higher dorms. It not only shows how much you know about the current meta but shows your knowledge in cards that can wreck your opponents deck leaving him or her with very few if any options.

1) What is a Side Deck?:

Quote :

It is a collection of between 0 and 15 cards, separate from the Main Deck. The Side Deck is used in Matches between Duels, to alter the contents of the Main or Extra Deck. Previously, the Side Deck could not be used to alter the contents of the Extra Deck, though this has been changed.This is done to better suit a strategy against an opponent's Deck or improvement your own deck by changing how it plays or making it stronger and more consistent.

2) What do you Need for Proper Side Deck:
15 cards that can wreck your opponents deck or prohibit certain cards or moves. You could also switch your main deck from one type to another which is called a smokescreen but we will get to that later.

3) How to Build a Competitive Side Deck?
1) You need knowledge of proper meta decks and what makes the decks work
2) You need to find cards that either prohibit moves or shutdown the deck completely.
3) Put those cards in the Side Deck.

4) Example of Side Decks:

Examples:

5) Why is Important to Use a Side Deck in Competitive Duels?
It is important because most decks that are competitive are high tier decks and siding vs them will allow a better chance to win vs those decks. Not siding in your deck is basically saying you do not want to make it hard for your opponent to beat you .To win a YCS, you need to understand the meta and learn about to counter them by do a complete side deck.

6)Different Types of Siding
We have three different types of siding styles you can accomplish
6A)Improvement Siding (Beginner)
6B)Competitive Siding (Beginner to advance)
6C)Smoke screening


6A) Improvement Siding- This type is siding is used for beginners or people testing a deck where they have a bunch of cards in the side deck and they do not know if they should be added to main deck or not.
Example:suppose i was making a Superheavy deck and i wanted to negate my opponents effect or negate it when it targets my monster. however that card needs to be able to remove itself from my grave to work with my synchros who's effects only work if i have no spell or trap cards in my grave.

Example of Improvement Siding


6B) Competitive Siding - This is the most popular siding type for competitive duel whether it is rated on dueling network or first round of a YCS. This type of siding is for advanced players who know not only the current meta or popular decks, but also know what cards would be great to side vs those decks allowing you to make it easier to win vs meta decks.

Example of Competitive Siding.


6C) Smokescreen Siding - This type of siding is for advanced players to expert players who know how to counter the other of other decks. Basically what you do is you change your deck from one type of deck to another so the siding is much harder on your opponent while allowing your deck to be unaffected by the new change to the deck.
Example of Smokescreen Siding


Noticed i did not do any of changes to affect the decks to show each example. its based on player preference or what deck your facing to change the decks. Depend on how much experience you have, this may be easier or harder to accomplish depending on deck.

7)Hybrid deck
A hybrid deck is two or more types of decks working together to form a fluent deck with being good and competitive.
a more popular version of this example if when the deck H.A.T. which stands for Hand archetype, Artifact archetype and Traptrix archetype together which became popular during its prime use as a popular meta deck.
Example of Hybrid


What to figure out when building a hybrid deck?:

7A) Make sure the deck has one common factor to keep them working together (see the fire-fist constellar build i posted).7B) Try to make sure the archetypes do not throw each other off.7C)Test out every build you make to see if you can get it working.

Good article batman, i have few addendums to add. 

It's also important to make your side-deck based on what you expect to face and on what you fear would hurt your deck the most. 

As shown in your good examples of side decking, there are cards that hurt several meta decks at the same time, i.e 'Mistake', 'Mind Crush', 'Imperial iron wall' and 'Veiler'.. etc 
It's a good idea to use cards such as these to be prepared against multipuble decks.

dat side deck is nab

diz haw u do side dick

LoudFist wrote:

Good article batman, i have few addendums to add. 

It's also important to make your side-deck based on what you expect to face and on what you fear would hurt your deck the most. 

As shown in your good examples of side decking, there are cards that hurt several meta decks at the same time, i.e 'Mistake', 'Mind Crush', 'Imperial iron wall' and 'Veiler'.. etc 
It's a good idea to use cards such as these to be prepared against multipuble decks.

i already talked about that.......i will add this quote to it cuase it mentions a bit on what cards hurt your deck the most.