Three is definitely better but a lot of places do go by the two-second rule.
And obviously use the visual aid if there is one. The point is to learn to use a fixed point to time it. If you only learn to count how many dots/lines there are, you might struggle when there aren’t any obvious markings.
Your last point is fair! I didn’t mean to imply that you should only use markings. It sounds a bit stupid to still reach the two second rule though, since the average reaction time seems to be 1-1.5s. If you need to break abruptly 0.5s won’t get you very far.
Three is definitely better but a lot of places do go by the two-second rule. And obviously use the visual aid if there is one. The point is to learn to use a fixed point to time it. If you only learn to count how many dots/lines there are, you might struggle when there aren’t any obvious markings.
Your last point is fair! I didn’t mean to imply that you should only use markings. It sounds a bit stupid to still reach the two second rule though, since the average reaction time seems to be 1-1.5s. If you need to break abruptly 0.5s won’t get you very far.