I received the Whodunnit? Series 1 DVD set today, and have already watched the entire first disc this evening!
For anyone who's never seen it, here's a pen picture: there's a host, a celebrity panel, and a studio audience, all of whom watch a pre-filmed mystery in two parts, the aim being to work out who the criminal/murderer was. This is done by comparing different suspects' statements about what they were doing, where they were, what they saw or heard, etc, at the time of the crime (there's usually a detective asking questions or someone filling that role, like a doctor). Once the main part of the tale is told, the panelists then get to re-watch a 20 second clip of their choice from the film, and ask suspects questions to try to work out which of them is lying, what motive for the crime they had, and to piece together the facts from the red herrings. The panel then say who they thought dunnit and why, and a member of the studio audience who got it right wins one of a selection of props used in that episode (an imaginative idea!), before the real murderer is asked to stand up (cue movement amongst several of the suspects as a final tease before the murderer actually stands!), and all is revealed...
Whodunnit? always had a certain something as a TV experience, despite arguably lacklustre acting from some of the cast of suspects (counterbalanced by some good and well-known character actors), and occasionally unsatisfying plots: for one thing, it's about as interactive as you could be back in the 1970s (the two ad breaks doubled up as thinking/discussion time at home before the next part began), and working out whodunnit was (and is) always fun.
I doubt I was old enough to have seen this first Edward Woodward-hosted series - my memories are of the later (more polished) Jon Pertwee-hosted shows - but you can see them refining things as they go even in this first, cautious year.
Each episode improves on the last in terms of presentation. I would suggest watching the pilot last, because it's a very creaky, quite wooden thing - shorter than the rest of the series' episodes (30 mins against 45 mins), and hosted by Shaw Taylor (then host of the "Police 5" five minute proto-CrimeWatch type shows) with Woodward as a panelist (they obviously realised it worked better the other way round because when the first episode proper was shown, Woodward was then host with Taylor as a guest panelist).
It's satisfying to see the production team clearly having reviewed how each episode went and then taken steps to refine one aspect or another for the next one, trying different ways of presenting the whole thing until they (eventually!) got the magic combination right. For one thing, in the later episodes I must have seen live (then with Patrick Mower and Anouska Hempel as regular panelists), when the murderer has been revealed, they went to the trouble of actually showing the crime being committed in flashback, often narrated by the killer (something they didn't do in this first series: once the murderer is revealed, Woodward quickly mentions a couple of clues, and that's it! End of episode. It's all rounded up a bit too quickly).
Woodward is a personable host in this first series - moreso as the episodes continue - but he's less smooth and at ease than I remember Pertwee was (presumably that's why he stopped hosting it after one series). Pertwee is a guest panelist for one of these episodes and must have enjoyed the experience as he went on to host the remaining years of the show.
It influenced the later "Cluedo" TV series in the early 1990s, and I think there was a later one called something like "Watching the Detectives", and another espionage variation was "Masterspy" (with William Franklin), all three of which had a similar format and clearly owe their existence to Whodunnit? (although arguably none was as good as Whodunnit? at its best).
Highly recommended, partly because there's never been anything else quite like it on TV! I'm really looking forward to the Pertwee years being released in due course (fingers crossed), because when they got that magic formula right, really cranking up the tension, drama and expectation like the best mystery series can, this was superb television.