a bad workman always blames his tools

a bad workman always blames his tools

If someone performs a job or task poorly or unsuccessfully, they will usually lay the blame on the quality of their equipment, or other such external factors, rather than take responsibility for their 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.
See also: always, bad, blame, tool, workman