Reading a Margin: Why the Vote Gap Alone Tells You Nothing

A margin of 120 votes tells you nothing until you know what it is 120 out of.

In a ward it can be decisive. In a county it is a rounding error. The number on its own is not information, and treating it as information is how a perfectly ordinary result becomes a controversy.

Turn the gap into a share before you say anything

A margin belongs in percentage points of valid votes, not in raw votes.

Suppose an MCA race in a ward of 10,000 registered voters produces 6,000 votes cast, 5,800 of them valid, and the winner finishes 120 ahead. That gap is about two percentage points of the valid vote. Now it is comparable to something. A 120-vote gap in a constituency where tens of thousands voted is a fraction of a point, and a fraction of a point is a different animal altogether.

Do this conversion first, every time, before forming an opinion. The raw number is designed by nature to mislead, because human beings are bad at holding two scales in mind at once.

Compare the margin to things that could actually move it

Three comparisons, in order of usefulness.

Compare the margin to the rejected-ballot count. If more papers were set aside than separate the top two, the result stands but it cannot be checked without reopening the pile. Related: what a rejected ballot is.

Compare the margin to a single polling station. If one station's entire electorate is larger than the gap, then one station's dispute is capable of deciding the seat, which tells you exactly where the scrutiny should go.

Compare the margin to the number of stations in the contest. A gap of 120 votes spread over 30 stations is four votes a station. A gap of 120 that sits almost entirely in two stations is a different fact about the same election.

Percentage points and per cent are not the same word

This one costs people their credibility in public.

If a candidate's share moves from 40 per cent to 44 per cent, that is a rise of four percentage points. It is also a rise of ten per cent, because four is a tenth of forty. Both sentences are true, they describe the same movement, and they sound wildly different.

Use percentage points for changes in a share. Reserve per cent for the share itself. When somebody quotes a dramatic percentage increase in a vote share, check which of the two they mean before repeating it.

A plurality is not a majority

In most Kenyan contests the candidate with the most votes wins, even with well under half of them.

Six candidates splitting a ward can produce a winner on a share that would be a humiliation in a two-horse race. That winner is fully and properly elected. What they do not have is evidence that most voters wanted them, and reading a crowded-field plurality as a mandate is a mistake that has ended more than one political career at the following election.

The presidency is the exception, and it is the exception on purpose. A presidential winner needs more than half of all votes cast and at least 25 per cent of the votes cast in each of at least 24 counties. Related: how that second condition works.

What "close" means for what happens next

Close is not a mood. It has consequences with deadlines attached.

Election petitions other than presidential ones are filed within 28 days of the declaration of the result. A presidential petition goes to the Supreme Court within 7 days of declaration and is determined within 14 days. Those clocks start whether or not anyone has finished arguing on television.

That is the practical reason to size a margin properly on the night. If the gap is smaller than the rejected pile, or smaller than one station's register, the evidence that would support a petition is the signed station forms, and those need to be in hand within days rather than weeks.

So before 10 August 2027, decide in advance what your own threshold is. Write down the margin, in percentage points, below which you will collect every station form in the ward without waiting to be asked. Deciding that number while nobody is shouting is worth more than any amount of energy spent deciding it afterwards.