This is a house decision, not a personal style
Bars fall into three camps, and you do not get to pick which one you are in:
- Jigger houses. Everything measured, every time. Standard in craft cocktail bars, where consistency is the product.
- Free-pour houses. Counted pours from speed pourers. Standard in high-volume rooms — nightclubs, dives, sports bars — where the seconds matter more than the eighth-ounce.
- Mixed houses, which is most of them. Free-pour the highballs and the wells, jigger the cocktails and anything premium.
Ask on day one which you are in. Then do that, even if you think the other one is better.
Why houses care so much
Pour cost. If your house spec is 1.5 oz and you are pouring 1.9 oz because you never checked, a 750 ml bottle yields about 13 drinks instead of 17. That is roughly a quarter of the bottle given away, on every bottle, all night.