What's the biggest score you've ever achieved on a single hand? I think a grand slam redoubled and vulnerable losing all 13 tricks must be the max and that would 'achieve' minus 7600 though in practice, quite an improbable score!
The above hand looks fairly innocuous. Nobody can make a game and you would expect one side or the other to end up in a part-score, certainly not 7NT redoubled! Let me explain.
Having got bored with Candy Crush, out of curiosity I thought I'd try playing a few hands on BBO (Bridge Base Online) where you can just join a casual game with three other unknown players. Not sure how the scoring works but it is 'imps' so some kind of teams scoring and when I joined I found myself partnering Isabella from Italy whose current score was minus 52 imps. I don't know if this is why her previous partner had left the table but anyway we played a couple of hands and I quickly realised nobody had much beyond a basic understanding that it was Strong No Trump, Stayman, Transfers and weak Twos.
On the first hand I watched Isabella play herself off in a cold 3NT and on the second hand the opposition could have bid a lucky slam but only got as far as 3 Clubs.
The above hand then came up and I hoped I might be able to reach a decent contract, maybe in spades or No Trumps. However, I was fourth caller and Lois from the USA opened a strong No Trump to my left which was passed round to me so I doubled. It was then passed round to Leo from Poland who bid 2 Clubs. Much as I would like to have bid something, I was on best behaviour so I refrained and Lois bid 2 Hearts. Partner passed and Leo bid 3 Clubs but Lois was having none of that and bid 3NT. I didn't really know what was going on but I was just contemplating a friendly double but before I had the chance, the already bizarre bidding went completely crackers when Leo raised to 7NT. Well I couldn't resist that so I doubled but that wasn't quite the end of the auction as the redouble card then landed on the table! Partner led a small diamond but by the time dummy appeared, a robot appeared in the East seat and Leo had vanished, probably with a few Polish swear words!
It wasn't too difficult to defeat the contract. Declarer won the first trick, switched to the King of hearts. I didn't bother to duck, played the King of spades then returned partner's suit and, after running it, bless her she returned a spade, not the Queen unfortunately but Declarer had discarded the Jack of spades from dummy and the 7 and 10 from her own hand so I was able to 'risk' the 9 then play the Ace to crash partner's Queen and collect several more spade winners. 7NT redoubled went 10 down for minus 5800. I don't remember ever scoring anything even half that and I'm always quite happy with an occasional plus 800.
Nothing so spectacular has happened since but the random deals online are often quite entertaining and from someone who never wanted to play online, I actually quite enjoy it. These casual games are free by the way and you can also play with your own partner so a good opportunity to have a practice and make sure you don't have any similar misunderstandings. Despite the above fiasco the standard of Bridge is variable though not unreasonable but obviously the bidding is pretty unsophisticated. I haven't yet tried playing with a regular partner but if you are playing against another regular partnership I expect you would get a better game.