As Raindance and Haymaker become all the more popular and Jungle is released 
many wonder how they can win a Tournament without using a Raindance, 
Haymaker, Pokémon Center or Damage Swap deck, all expensive decks, my simple 
answer, Disruption.  All of the popular decks have a very tightly focused 
strategy, good because it allows the accomplishment of a goal quickly, bad 
because it allows for easy disruption, but be warned, disruption is very case 
sensitive, and for each type of deck you want a different kind of disruption, 
I will explain to you the basics of disruption, give an example of a 
disruption deck and then you can do the rest.

Of all the aforementioned decks Damage Swap and Pokémon Center are the most 
easily disruptable, because of greater energy requirements then Haymaker and 
Rain Dance.  The best cards for diruption are Energy Removals, Gust Of Wind, 
Lass, Impostor Oak, and Switch.  Energy Removal is probably the most obvious, 
use this in combination with Item Finder and you can set your opponent back 
by many turns, Energy Removals are very dangerous and are a must for any 
disruption deck.  Moving on we have Gust Of Wind, I can't say enough about 
the versatility of this card, it can be a game winner and a life saver.  It 
allows you to bring out the often weak and energyless benched Pokémon and 
knock them out before your opponent can do anything, but be warned, don't 
take chances using this card, never bring out a Pokémon that may end up 
killing you before you can kill it, bring out Pokémon that are damaged and/or 
energyless.  Lass, the reason I put this card is obvious, it can interfere 
with almost all of the popular deck types, with the exception of Haymaker, 
which is not as reliant as the others on trainers.  If your opponent has a 
breeders and evolutions in his/her hand use Lass to get rid of the breeders 
and slow down the evolution.  Impostor Oak, another obvious card, so your 
opponent just uttered the typical "YES!" then use Impostor Oak, it can set 
them back many turns.  Switch, of all the disruption cards this is the least 
obvious, but one of my favorites, got a nice built up Pokémon on your bench 
and a paralyzed active Pokémon with only ten HP left, switch it, yet another 
lifesaver.  Now onto Pokémon, the most obvious disruptors are Dragonair and 
Mewtwo, Dragonair is energy destruction while Mewtwo can in many cases knock 
out a built up Pokémon in one or two hits.  Poliwrath is another good 
disruption card, his attack is like Dragonairs but is does 20 more damage.  
Free retreat Pokémon are also very useful in disruption decks, Butterfree 
being a very good example, his atack allows you to switch the defending 
Pokémon with one from the opponents bench, the only drawback being that it is 
the opponent's choice, add Mega Drain a great all around attack and free 
retreat and you have a very good card.  Retreating is one of the simplest and 
most negelected forms of disruption.  Dodrio is one of the most under rated 
cards I have seen, but his Pokémon power makes him great for stall and 
disruption decks, allowing you to retreat many Pokémon for free, as long as 
he is on your bench.  His attack is also good, although it is overcosted, 
still it can deter attacks giving you time to build up your bench.  So with 
all that said here is a example of a disruption deck.

Pokémon
2 Mewtwo (Kill Biggies)
1 Lickitung (Stall)
1 Kangaskhan (Stall and Draw)
1 Scyther (Free Retreat, Relatively good attack)
1 Spearow (Mirror Move is another Attack deterent, plus free retreat)
2 Dratini (to get Dragoniar)
1 Dragonair (ALWAYS in a disruption deck ALWAYS!)
2 Doduo (More Freee Retreat)
1 Dodrio (Retreat costs lowered)
2 Gastly (Could be replaced with two Dratini)
1 Haunter (Could be replaced with another Dragonair)
4 Caterpie (For Butterfree)
2 Metapod (Also For Butterfree)
2 Butterfree (Power, and more free retreat)

Trainers
2 Bill (Drawing)
1 Item Finder (Get Back NRG Removals/Retrivals)
1 Scoop Up (Pure Disruption)
2 Potion (Preserve your Pokémon!)
2 Switch (Retreat!)
2 NRG Removal (ALWAYS In a Disruption Deck, ALWAYS!)
2 NRG Retrieval (This deck has low energy)
3 Gust Of Wind (Get 'em while there weak!)

Energy
10 Psychic
10 Grass
2 DCE

Notice a few things about this deck, beacause of the card variety it has lots 
of different weaknesses, a good thing, almost all of the Pokémon in this deck 
have a resistance, except Mewtwo, Caterpie and Metapod, another very good 
thing.  This deck is designed to be adaptable, the Psychic Pokémon can easily 
be modified, as can the Colorless, although Dragonair is a must, the energy 
works out pretty well because of the retirevals, alhtough Energy Denial can 
pose a threat.  This deck is very customizable, so go out, disrupt and 
destroy, and don't forget about retreating!

Jim McGarity, Ivy Gym Leader