a bad workman always blames his tools
If?someone?performs?a?job?or?task?poorly?or?unsuccessfully,?he?or?she?will?usually?lay?the?blame?on?the?quality?of?his?orher?equipment,?or?other?such?external?factors,?rather?than?take?responsibility?for?his?or?her?own?failure. The football player blamed the overinflated ball for costing his team the game, but as they say, a bad workman always blames his tools.