What unlimited is for
The daily board is a puzzle with a finish. Unlimited is a workshop. Use it when a category keeps beating you, when you want to feel a ratio in your hand before you spend a weighted round, or when midnight is still hours away and the day's five are already done. The lock-in still draws the truth in red. The score on each pair still follows the same ratio curve. The difference is that the next pair is new, and there is no 1,000-point ceiling waiting at round five.
There is no streak on this mode. A streak is a count of finished daily boards, stored in this browser. Unlimited can run for an hour and still leave that count untouched. That split is the point. Practice should not be able to counterfeit the shared day.
How a pair is chosen
A pair needs two different objects on the same kind of measurement. Length with length. Area with area. A country area and a bus length are refused, on this page and on the compare page, because a ratio between them would be a unit error dressed up as a score. The library also skips pairs that are almost the same size, and pairs so far apart that the picture stops teaching. What remains is a band where a careful eye can be wrong in an interesting way.
The starting white silhouette is not the truth and not a polite near-miss. It is placed somewhere in the legal range so you have to look. The range of the slider is based on the reference alone, wide enough that the answer is not implied by the ends of the track. If you find yourself using the track ends as a hint, you are reading the tool instead of the objects. Zoom out and look again.
A way to practise that actually transfers
Pick one error and stay with it. People who underestimate tall thin things should stay on landmarks for a while: the Eiffel Tower at about 330 metres against the Statue of Liberty at about 93 metres including the pedestal is a clean lesson in 'the famous one is not the taller one by the margin your postcard suggests.' People who crush large animals into the size of vehicles should put the 27-metre whale next to the 12-metre bus until the multiple feels boring. Boring is the goal. The daily board is where surprise belongs.
Say the ratio out loud before you lock in. 'About twice.' 'A little over, not double.' 'Half, maybe a bit more.' The score agrees with that sentence more than it agrees with a vibe. Within 6 percent is a tight call and scores 100. Twice as big, or half as big, scores 45. If your spoken ratio was 'about the same' and the red shape is twice the white one, the miss was not bad luck. It was a wrong sentence.
Use the category shelves as drills, not as a tour. Animals train body length against height. Vehicles train bumper-to-bumper length, from a bicycle up to a container ship of about 400 metres. Space trains ratios that feel unreal because the pictures in textbooks are cropped. Geography is the shelf where people mix up length and area. Unlimited will not stop you from learning the wrong axis if you skip the question. Read it.
What unlimited will not do
It will not show you a global ranking, because this site does not have accounts and does not collect a score from your browser onto a server. A leaderboard would need that collection. We do not run one. It will not repeat the daily answers as a shortcut. If you want today's five explained after you have played them, that is the answers page, and it waits until you finish or until you choose to look. Unlimited is a different draw.
It will also not make a thin guess into a good one by volume. Fifty careless locks teach the hand to hit the button. Five slow locks, each with a spoken ratio, teach the eye. The red outline is the same teacher in both modes. The only habit worth building is to look at where the red edge falls, then name the direction of the miss, before you ask for the next pair.
Scoring, units, and stopping
Each unlimited lock uses the same curve as a daily round. Within 6 percent scores 100. A ratio of two scores 45. A ratio of five scores 0. There is no double or triple weight, because there is no fifth round. The running total on the board is the sum of the locks you have made in this sitting, over the count of those locks. Leave the page and that sitting ends. The daily store in this browser is a different record.
The unit button still switches metres and feet for the labels. The underlying comparison does not change. A ratio is a ratio in either unit. Stop when the misses get sloppy. The library is large enough to keep offering pairs. Your attention is not. Tomorrow's weighted rounds will go better if you stop while you can still say, in one sentence, what the last red outline did to your guess.