This is the 18275th most frequent Russian word.
шахматиста
Chess player.
Here, 'шахматиста' is the genitive case of 'шахматист', indicating the object of the verb 'играл против', expressing whom the speaker played against.
Вчера я играл против опытного шахматиста.
Yesterday, I played against an experienced chess player.
In this sentence, 'шахматиста' is in the accusative case because it is the direct object being listened to by the club members.
Шахматиста выслушали на собрании клуба.
The chess player was listened to at the club meeting.
Here, 'шахматиста' is in the accusative case again since it is the entity being nominated by the participants for the tournament.