Bill Sefton
... that when Bill Sefton raised the pole vault world record to 4.54 m (14 ft 11 in), he could not try to improve it further as the uprights did not go any higher?
... that when <b id="mwDEo"><a href="./Bill_Sefton" id="mwDEs" rel="mw:WikiLink" title="Bill Sefton">Bill Sefton</a></b> raised the <a href="./Pole_vault" id="mwDEw" rel="mw:WikiLink" title="Pole vault">pole vault</a> <a href="./Men's_pole_vault_world_record_progression" id="mwDE0" rel="mw:WikiLink" title="Men's pole vault world record progression">world record</a> to 4.54<span id="mwDE4" typeof="mw:Entity"> </span>m (14<span id="mwDE8" typeof="mw:Entity"> </span>ft<span id="mwDFA" typeof="mw:Entity"> </span>11<span id="mwDFE" typeof="mw:Entity"> </span>in), he could not try to improve it further as the uprights did not go any higher?