Finding the typo when a description does not close
When a description misses by feet rather than hundredths, there is usually one bad call. The size and direction of the misclosure are often enough to tell you which one.
Start with the error bearing
A single blunder moves every point after it by the same amount, so the misclosure points along the error. Compare the error bearing with the calls in the description before rechecking every digit.
Common blunders and what they leave behind
| Blunder | What the misclosure looks like |
|---|---|
| Wrong distance on one course | The error bearing runs parallel to that course, and the error equals the amount the distance is off. |
| N and S swapped | The error runs due north or south, and it is twice that course's latitude. |
| E and W swapped | The error runs due east or west, and it is twice that course's departure. |
| Bearing written in reverse | The error is twice the course's length, running along the course. |
| A course left out | The error distance and bearing match the missing call. |
| Curve direction wrong | The end of the curve swings to the other side of its chord. Curves are worth checking first when one is present. |
Transposed digits
Swapping two neighboring digits, such as 152.40 typed as 125.40, is one of the most common slips. Bookkeepers know the tell: the difference between the right and wrong values is a multiple of 9 in the place where the swap happened (152.40 − 125.40 = 27). Degrees and minutes can also be traded, as when 23°41' is typed as 41°23'.
Text that was misread
Descriptions copied out of scanned or converted PDFs can pick up characters that look right but aren't, such as the letter O for a zero or a lowercase l for a one. Compare the parsed rows against the original whenever the text came from a PDF.
Letting the checker search
The checker tries each of these single changes on every course: flipping N and S or E and W, reversing a bearing, trading degrees and minutes, transposing digits, reversing a curve, and changing a distance along the line of the misclosure. It lists the changes that would bring the description within your precision threshold, most specific first, and you can apply one with a click to see the result. A suggestion is a lead, not an answer. Confirm it against the plat or the field data before changing the document.