Club Sliven 2000 มีกัปตันทีมกี่คน?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
How many different team captains does the club Sliven 2000 have?It is not neccessary to use all the tables.
 table_23214833_1:  (team_captain [ VARCHAR ] club [ VARCHAR) ]
SELECT COUNT(team_captain) FROM table_23214833_1 WHERE club = "Sliven 2000"