Dead heat
Etymology
From horse racing, where a "heat" was a single race or round (from the sense of one burst of running), and a "dead" heat was one with no live result to separate the horses. It predates photo-finish cameras, when judges simply could not split the runners. It now names any exactly tied contest, especially a close election.
noun phrase · /DED HEET/
A finish so close that two or more competitors are judged to have tied exactly.
What it names
The true tie — not a near-miss but a result too close for any winner to be separated.
Example
The two ballot measures finished in a dead heat, forcing a runoff.
Related idea
A dead heat is a genuine tie at the finish, whereas a stalemate is a deadlock during play, where no one can even reach a finish.