>This is one of my decks and i would like some help with it
>
>Double-Down
>
>Pokemon(15)
>2 Chansey
>2 Arcanine
>3 Growlith
>2 Kangaskhan
>1 Snorlax
>1 Moltres
>4 Magmar(Fossil)
>
>Trainers
>2 Professor Oak
>2 Super Potion
>2 Bill
>4 energy Removal
>4 Gust of Wind
>2 Potion
>2 Switch
>2 Gambler
>
>Energy(25)
>25 Fire

Let's start with the pokemon. First, let's get rid of Snorlax. Having only 1 isn't really helping our cause here, and we have a lot of fighting weak, colorless pokemon already by the Chanseys and Kangaskhan. Let's up our Moltres to 2 to compensate for our fighting weak pokemon, and up our Growlithe/Arcanines to 4-3.

Pokemon (14 Basic + 3 Evols = 17 Total):
4 Growlithe
3 Arcanine
4 Magmar (Fossil)
2 Moltres
2 Chansey
2 Kangaskhan

Most fire decks that are built are energy-intensive. What I mean by this is they tend to have attacks that force you to discard energy. In the ones you've chosen, for instance, Moltres and Arcanine both have attacks where you have to remove Fire energy from the pokemon. Do to this fact, fire decks tend to run (or do better when they are) a higher number of Energy than regular decks. This is one of the rare decks that defies my usual 20/4 philosophy. In fact, 22/4 is what I'd recommend for a deck like this.

Energy (22 Basic + 4 DCE = 26 Total):
22 Fire
4 Double Colorless Energy

That leaves us with (60 - 17 - 26 = 17) 17 slots left for trainers. Let's make good use of them by adding card drawing power, energy retrievals, switches and scoop ups for the pokemon we have with high retreat costs, and a few cards to mess with our opponent's game plan.

Trainers (17 Total):
4 Bill
1 Professor Oak
1 Gambler
2 Energy Retrieval
2 Switch
2 Scoop Up
3 Gust of Wind
2 Item Finder

You should be able to get out a Kangaskhan or Magmar to start the game, then either Fetch or Smokescreen/Smog to start off. Start building up to an Arcanine to start hitting heavily and then prepare a Moltres for WildFire. It is a strong deck and should do fairly well.