The decisive moment (Cartier-Bresson's idea) is about anticipation - reading the scene, predicting the peak, pressing the shutter at exactly the right time. It requires patience and spatial awareness.

The lucky accident is different. Shoot a lot. Move fast. React. Some of the best frames will surprise you on the light table.

Neither approach is superior. Most photographers use both without realising.

Watch for: relying too heavily on one. If you only wait for the decisive moment, you miss the chaos. If you only spray and pray, you stop reading scenes properly.

The point: know what you're doing and why. Then do it on purpose.