The original play by Anthon Shaffer opened with Anthony QWuayle and Kieth Baxter in the lead roles in 1970 before running for some 1200 plus performances on Broadway also with Quayle in the lead, Patrick MacNee taking over later.
It was rapidly followed by the 1972 film directed by Joseph Mankiewicz with Laurence Olivier and Michael Caine to the playwright's own script. The plot is si9mple - a games loving best selling mystery writer persuades his wife's young lover to visit him in his country house, purportedly to discuss a divorce, but then plays a self-devied game with him. The film is set in a traditionally styled house (athelhampton in reality) with all the expected appurtenances of a rich country gentleman's life. The stage origins are emphasised by the opening shots which move in from a proscenium surround to the house's grounds. Olivier displays his usual run of histrionic tricks and funny voices in something of a virtuoso display to which caine as a half-Italian up-and-coming fashionable hairdresser responds in a much less flashy style - rather Harry Palmerish with emotion. This was Mankiewicz's last film and it does nothing to damage his reputation with few wasted shots and scenes, the two hours plus passing effortlessly in what is very much only a slightly opened out version of the stage play: effortless directing and excellent acting together give the film a high rating.
Kenneth Branagh refilmed the play in 2007 with a script by Harold Pinter with Michael Caine again, this time in the role of the writer and Jude Law in the role Caine had in the first film. Still set in a cvountry house but this one with an ultra-modern interior designed by the wife and with far less emphasis on games. The main differences are firstly, the debasing of the language to the extent that it seemed that every other word was either f...ing or c..., completely unnecessarily, secondly, that Law is now an out-of-work actor who also does hairdressing and thirdly, and most importantly from a cinematic point of vierw, Branagh seems to have discovered that cameras can be angled to record scenes or part scenes from ridiculous angles, none of which are in the last way helpful to developing or understanding the plot. With Caine's non-theatrical background, his role is far less histrionic than the Olivier one and `law again shats that, pace 'Alfie', he should not essay repeats of roles previously played by Caine. Seeing the two films back to back (though the eaelier one seen secondly was skip-watched) makes for the comparisons suggested but the more recent film has moved sufficiently away from the play that it is almost a different story and deserves to be considered in isolation, hard though this is to do (how does one dismiss memories). of the two, the former is the better film, even with Olivier, and the latter would be a better film, even with Law, had Branagh restrained himself
A far more complete and therefore better review than mine, but I think we agree which of the two films is the superior. I still can't believe that for once a remake was shorter than the original but as you rightly point out they are, in the end, really two different movies starting from the same basic plot but moving in wildly different directions.