Methodology

Everything runs in your browser

GolfVectorLab has no account system, no server-side calculation, and no database that stores your golf information. When you use an engine, the arithmetic runs on your own device using the values you typed in that session. If you choose to save a bag distance or a Handicap Index for reuse, it is written to your browser's local storage on your device, not to a server GolfVectorLab operates. Clearing your browser data removes it. Nothing you enter into an engine is transmitted anywhere as part of getting your answer.

Two kinds of results

A GolfVectorLab result is always one of two kinds, and the engine tells you which one you are looking at:

A rule-derived result follows a published formula exactly, using inputs you supplied, such as a Course Rating, Slope Rating, and Handicap Index producing a Course Handicap under the World Handicap System. Given the same inputs, a rule-derived result should match the same calculation performed by any correct implementation of that rule.

An estimated result uses your own measurements, a stated assumption, or a proxy value where a precise input is not practical to collect, such as a planning range built from a handful of self-reported carry distances. An estimated result always states the sample it is built from and shows a range rather than a single confident number when the underlying data does not support one.

A small number of engines may not have enough information to produce either kind of result yet. Those engines say so directly rather than guessing, and stop short of a recommendation until better input is available.

Where the golf formulas come from

Handicap and scoring concepts reference published USGA and The R&A material for the World Handicap System, current as of the review date shown on the sources and assumptions page. Bag and distance reasoning is built from the player's own reported measurements rather than a manufacturer's stated carry numbers, because a manufacturer average does not reflect an individual player's swing. Condition-adjustment reasoning states its assumptions plainly and is scoped for practice and casual-round planning, not tournament decision-making.

What a visual adds, and what it does not

Where GolfVectorLab shows a chart, map, or matrix, that visual is generated from the same typed data model behind the plain-text answer, and it is never the only way to see the result. Every visual engine also provides a table or written equivalent, so the information is available whether or not the chart itself is useful to you.

What GolfVectorLab does not attempt to calculate

GolfVectorLab does not post scores to an official handicap record, issue a Handicap Index, pull live course or GPS data, or give a ruling on the current Rules of Golf. Where a question depends on an official record or a live rules decision, the relevant page says so and points to the governing body responsible for it.