To win consistently on the competitive ladder, every single deck must be built around a specific, reliable 'Win Condition'.

It is the card that mathematically guarantees tower damage if supported correctly, bypassing or overwhelming the enemy's defenses.
What Makes a Win Condition?
The most reliable Win Conditions are troops that are programmed specifically to ignore all enemy units and target buildings exclusively.

If your opponent can easily prevent your 'attacker' from ever touching the tower using cheap distractions, it is not a true Win Condition.
You will draw constantly.You can have a secondary win condition.The other seven cards in your deck exist solely to ensure your Win Condition reaches the tower safely. Categorizing Win Conditions
They rely on overwhelming the opponent with sheer stats and raw hitpoints during the double elixir phase.

Fast Punishers (Hog Rider, Ram Rider) are the core of Cycle and Bridge Spam decks; they are cheap, incredibly fast, and demand an instant reaction.
The StrategyTop CardsExecutionHeavy Beatdown TanksGolem, Lava Hound, Electro GiantBuilds a massive 15-elixir push that is mathematically impossible to stop in a single engagementFast Cycle PunishersHog Rider, Wall Breakers, BanditConstantly chips the tower for small amounts of damage by out-rotating the opponent's defenses Building the Perfect Deck
If your answer is "I hope my elite barbarians just run past everything," your deck is fundamentally flawed.

Find your condition, and execute it flawlessly.

Here's more info on tower rush look into the web-page.