Why do most two-element Yagis with normal spacing have a reflector instead of a director?

In a two-element Yagi antenna design with standard spacing (around 0.15 to 0.2 wavelengths), a driven element paired with a reflector produces slightly higher forward gain than pairing a driven element with a director. The gain difference is typically around 1 dB in favor of the reflector configuration. While both configurations provide directionality, the reflector arrangement optimizes the phase and magnitude of the mutually coupled currents to better reinforce the forward radiation lobe. Distractors like 'lower SWR' or 'greater front-to-side' ratio are incorrect because the primary advantage driving this standard design choice is the maximization of forward gain.