Here's what nobody's talking about: Alonso's tyres were getting faster, and Stroll's weren't. Alonso's degradation rate was -0.766 seconds per lap — negative, meaning he was finding time as the stint went on. Stroll? -0.072 seconds. Basically flat. That's the difference between a driver wringing performance out of a green track and one just managing temperatures.
Qualifying in Bahrain is about track evolution. The circuit gets faster every lap as rubber goes down. Alonso knew that. He pushed early, banked a baseline, then came back out for one more dig when the track was at its fastest. Stroll played it safe, waited for the perfect moment, and by the time he was ready to commit, Alonso had already locked in P6.