Why is it der Volleyballer?

Volleyballer ends in -er, and most nouns ending in -er are masculine: in a German dictionary, 86% of them take der.

All nouns ending in -er
Sense 1
der

Meaning

[1] Sport: Player of Sport Volleyball

[1] Sport: Spieler des Sportes Volleyball

Examples

[1] Beach volleyball is usually played with two volleyball players per team

[1] Beachvolleyball spielt man meist mit zwei Volleyballern pro Team.

Declension

1 Singular Plural
Nominativ der Volleyballer die Volleyballer
Genitiv des Volleyballers der Volleyballer
Dativ dem Volleyballer den Volleyballern
Akkusativ den Volleyballer die Volleyballer

In context

Dictionary entries include material from Wiktionary. Wiktionary