Die Quizrunde endet unentschieden; die Stichfrage bestimmt die Rangliste.

Because in German, all nouns are capitalized, not just proper names.

So here:

• Quizrunde
• Stichfrage
• Rangliste

are all capitalized because they are nouns.

All three nouns are feminine, so they take die in the singular nominative.

A useful extra point: with compound nouns, the gender is determined by the last part.

• Quizrunde → final part is Runde → die Runde
• Stichfrage → final part is Frage → die Frage
• Rangliste → final part is Liste → die Liste

So even if the first part changes, the last part decides the gender.

Because unentschieden is not a noun here. It is being used as an adjective.

In this sentence, it describes the way the quiz round ends:

• Die Quizrunde endet unentschieden.

So it stays lowercase.

Because it is a predicative adjective, not an adjective directly in front of a noun.

Compare:

• eine unentschiedene Quizrunde → adjective before a noun, so it gets an ending
• Die Quizrunde endet unentschieden. → adjective after the verb, so no ending

German adjectives usually have no ending when they come after verbs such as:

• sein
• werden
• bleiben
• and here, enden

This is just a natural German way of expressing the idea.

German often uses:

• unentschieden enden
• unentschieden ausgehen

Both mean that something ends in a draw or tie.

So endet unentschieden is idiomatic German. It is not a word-for-word match with English, but it is a very normal structure.

Endet is the 3rd person singular present tense of enden.

The subject is die Quizrunde, which is singular, so the verb must also be singular:

• die Quizrunde endet

This follows the normal present-tense pattern:

• ich ende
• du endest
• er/sie/es endet

The semicolon separates two independent main clauses:

1. Die Quizrunde endet unentschieden
2. die Stichfrage bestimmt die Rangliste

A semicolon is stronger than a comma but weaker than a full stop. It shows that the two ideas are closely connected.

You could also write this as two separate sentences:

• Die Quizrunde endet unentschieden. Die Stichfrage bestimmt die Rangliste.

But the semicolon neatly shows that the second clause follows directly from the first.

Because after a semicolon, German starts a new main clause.

Main clauses in German normally follow the verb-second rule:

• first element
• then the finite verb

So in the second clause:

• die Stichfrage = first element
• bestimmt = finite verb in second position
• die Rangliste = object

The semicolon does not make the second clause subordinate. It is still a full main clause.

Here die Rangliste is the direct object of bestimmt, so it is in the accusative case.

The verb bestimmen usually takes an accusative object:

• etwas bestimmt etwas

In this sentence:

• subject: die Stichfrage
• verb: bestimmt
• direct object: die Rangliste

Because Rangliste is feminine singular, its nominative and accusative article are both die, so the form looks the same:

• nominative: die Rangliste
• accusative: die Rangliste

It is a straightforward subject-verb-object sentence:

• die Stichfrage = subject
• bestimmt = verb
• die Rangliste = object

So the structure is very similar to English:

• The tie-break question determines the ranking.

This is a good example of standard German main-clause word order.

Because German very often forms compound nouns by joining words together.

Here:

• Stich
  • Frage = Stichfrage

German does this all the time:

• Haus
  • Tür = Haustür
• Fußball
  • Spiel = Fußballspiel

English often uses separate words or hyphens where German prefers one single word.

Yes, grammatically it is the ordinary verb bestimmen, and in this context it means something like:

• determines
• decides
• sets

So the idea is that the tie-break question decides the final order in the ranking.

Yes, for example:

• Die Quizrunde endet unentschieden, und die Stichfrage bestimmt die Rangliste.

That is also correct.

The difference is mainly stylistic:

• semicolon = a slightly more formal, compact way to link two closely related clauses
• und = more explicit and conversational

Both are possible, but the semicolon makes the sentence feel tighter and a bit more formal.