I spent the past weekend running a head-to-head experiment: five popular prompt engineering patterns, one real model (Claude Sonnet 4.5), fifty real movie reviews. The goal was simple — find out which technique actually delivers the best results.

The result? The simplest approach won. And the most sophisticated one — Chain-of-Thought — didn't just underperform. It actively made things worse.

Here's what happened.

The 5 Patterns I Tested

1. Zero-Shot

Direct instruction, no examples.

Classify this movie review as 'positive' or 'negative'. Reply with only one word.

Review: "The food was terrible but the service was great."

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2. Few-Shot (k=3)

Three input-output examples before the query.

Classify movie reviews as 'positive' or 'negative'.…