Fill four glasses to four different lines. Stop pouring at the exact mark on every one.
Four glasses sit on the bar, each with a red target line at a different height. You have one bottle and it pours nonstop while you hold your finger on a glass.
Touch and hold over a glass to start pouring into that one. The level climbs at a steady rate. Lift your finger to stop. Slide your finger to another glass and the pour follows you, so you can switch glasses without lifting.
A glass is satisfied once its level is inside the narrow band around the target line. Overshoot past the band and that glass is ruined — the round is lost and a fresh set of glasses appears with no score added.
Get all four glasses satisfied at the same time and the round counts. The next round pours faster and the tolerance band shrinks.
You have 60 seconds.
Goal: clear the most rounds.
Fill the tallest target first, the lowest last. The tallest line needs the most pour, and you might as well do that pour when there's plenty of margin everywhere else. Saving the low-target glass for last means you can sneak up on its small remaining gap with a brief tap instead of a long hold, and a brief tap is much easier to stop accurately.
When pour speed is high in later rounds, don't ride a single glass all the way to its band. The faster the flow, the more your reaction lag costs you. Pour partway, lift, switch to another glass, come back later for the final top-off. Splitting each glass into two passes lets you cross into the band on a short, late pour — which is the only time you can really see the band and stop without overshooting.