In a 2006 review of a later Churchill work, "The Independent"'s Paul Taylor described the play as one of the best dramas of the new millennium, and as "superbly compressed and economic". After watching a performance featuring John and Lex Shrapnel, Lyn Gardner of "The Guardian" dubbed the play "unchy, compact and endlessly inquisitive," arguing that it "is no simple warning against the perils of science messing with nature, but a complex and humane study of parental guilt, regret and responsibility and what it really means to be a father or son." Conversely, Jane Shillings of "The Telegraph" argued, "The highly wrought writing veers at times towards the mannered, leaving a faint sense that the style of Churchill’s play exceeds its substance, and the issue of cloning has lost its urgency". Don Aucoin of "The Boston Globe" praised the way the playwright "devotes no time to preamble or writerly throat-clearing, but plunges us straightaway into the play’s central dilemma". In the "Chicago Tribune", Chris Jones described "A Number" as "masterfully written".