Smart Timing Explained: How Strobe Paces Each Word

Everything starts from the base interval

Your speed setting defines one base interval: sixty seconds divided by the WPM. At 300 WPM, that is 200 milliseconds per word; at 500 WPM, 120 milliseconds. Every adjustment below is measured in base intervals or applied as a multiplier, so the rules keep their proportions at any speed.

With optional timing features off, an ordinary word gets one base interval. Compounds and acronyms receive additional time automatically.

Smart Timing: more time for longer words

With Smart Timing on, each character in a word adds a share of the base interval. The default Slowdown per Letter is 4 percent, so a four-letter word shows for 1.16 intervals and a ten-letter word for 1.4. Punctuation at the start or end of a word does not count toward its length.

Slowdown per Letter can be set from 0 to 50 percent. Minimum Word Length, from 1 to 15 letters, keeps shorter words at your exact speed, which slows long words without dragging out every short one. At 1, the default, every word is adjusted.

When Punctuation Pauses are off, Smart Timing also adds a flat 0.2 intervals to any word that ends in punctuation. When they are on, the pauses handle punctuation instead, so a mark is never timed twice.

Punctuation Pauses: duration by mark

Punctuation Pauses multiply a word’s time by the mark that ends it. The defaults are 1.5× for sentence ends, 1.3× for commas, colons, and semicolons, 1.4× for dashes, 1.5× for ellipses, and 1.2× for closing brackets and quotation marks. Each can be set anywhere from off to 4×.

Only marks at the end of a word count, so the period in 3.14 and the comma in 1,000 never pause. A sentence end has to be the last real mark in the word, which keeps an abbreviation such as “etc.,” from pausing as if a sentence had ended. A word that carries several marks, such as a closing parenthesis followed by a comma, pauses once, for the longest of them. The same rules cover Chinese, Japanese, and Arabic punctuation.

Blank After Sentences adds an empty screen after the last word of a sentence, from half a word to four words long at your speed. It skips abbreviations and initials, waits until the next word actually starts a sentence, and never appears before a new chapter.

Compounds and acronyms are always timed

Some tokens hold more than one word’s worth of reading. In a compound joined by a hyphen, en dash, or slash, each part after the first adds half a base interval, up to four parts: wedge-shaped gets 0.5 more, and state-of-the-art gets 1.5. Number units such as 10:30 PM and 44 B.C. stay together as one word and are timed the same way. A one-letter part adds nothing, so x-ray and T-shirt read like ordinary words.

Strobe adds a quarter of a base interval for each letter after the first in an acronym, up to 0.75: UK gets 0.25 more, FBI 0.5, and NASA or HTML 0.75. Three or more words in capitals in a row count as ordinary text unless commas, semicolons, or colons separate them, as in a list.

Neither adjustment has a switch. Both add time to the word before punctuation and complexity scale it.

Complexity Timing: quicker through the familiar

When you import a document, Strobe gives every word a complexity score between 0 and 1, computed on your device with Apple’s NaturalLanguage framework. The score weighs whether the word is on a list of common words, its part of speech, whether it names a person, place, or organization, its length, and whether it contains digits, mixed capitalization such as iPhone, or hyphens.

With Complexity Timing on, a word in the middle of the scale keeps its time, lower scores speed up, and higher scores slow down: the multiplier is 1 + 1.2 × intensity × (score − 0.5). In practice the effect is strongest on everyday words. At the default 50 percent intensity, words such as “the” and “of” run about a quarter faster, while rare words, names, and terms with digits get a little more time than average. Raising the intensity widens both effects.

Complexity scores are computed once at import. Playback uses the stored scores to adjust each word’s duration; this is the only timing adjustment that can shorten it.

How the adjustments combine

Strobe builds each word’s time in a fixed order. It starts from one base interval, applies Smart Timing, and adds any compound or acronym share. Punctuation Pauses and Complexity Timing then multiply the result.

At 300 WPM, with Smart Timing at 4 percent and Punctuation Pauses at their defaults, the word “room.” at the end of a sentence has four letters, for 1.16 intervals, and a sentence-end pause of 1.5×, for 1.74 intervals: 348 milliseconds. “FBI,” gets 1.12 intervals for its letters, 0.5 more as an acronym, and a comma pause of 1.3×, for about 2.1 intervals: 421 milliseconds.

Tune timing one feature at a time. Punctuation Pauses are a good first step because they mark the structure of sentences. Add Smart Timing if long words flash by too quickly, and Complexity Timing if common words feel slow. Keep the adjustments that make the stream easier to follow, and turn off any you notice more than the text.