their 1928–29 season
... that, during their 1928–29 season, Cardiff City F.C. were relegated from the First Division of the Football League despite conceding the fewest goals in the league?
... that, during <b id="mwB9g"><a href="./1928–29_Cardiff_City_F.C._season" id="mwB9k" rel="mw:WikiLink" title="1928–29 Cardiff City F.C. season">their 1928–29 season</a></b>, <a href="./Cardiff_City_F.C." id="mwB9o" rel="mw:WikiLink" title="Cardiff City F.C.">Cardiff City F.C.</a> were relegated from the <a href="./Football_League_First_Division" id="mwB9s" rel="mw:WikiLink" title="Football League First Division">First Division</a> of the <a href="./English_Football_League" id="mwB9w" rel="mw:WikiLink" title="English Football League">Football League</a> despite conceding the fewest goals in the league?