This cautious opening phase is actually a high-stakes psychological war of information gathering and scouting.

If you drop your primary win condition without knowing their defensive setup, you are relying entirely on blind luck.
The Art of the Cycle
You achieve this by playing 'cycle cards'—extremely cheap units that require some sort of response.

If they respond with an Ice Golem and a Musketeer, you can immediately deduce they are likely playing a fast cycle deck.
It is too risky.A log on the tower reveals their response.Note their preferred tiles. Tracking the Elixir Advantage
Information gathering is not just about knowing what cards they have; it is about knowing how much energy they have.

Tracking elixir is incredibly difficult at first, but it is the defining characteristic of a grandmaster-level player.
Opponent TendencyHow to Exploit ItAlways defending the bridge with a swarmPre-fire a predictive log or arrows exactly as your unit crosses the riverPre-planting defensesBypass their defense entirely Reading the Mind
When executed perfectly, a prediction looks like pure magic, but it is actually the result of meticulous information gathering.

Never play in the dark. Here's more info about tower rush review the web-site. Treat the first minute of the game as a reconnaissance mission.