IoS television review: The Aristocrats: Blenheim Palace, Channel 4, Thursday From Lord's to the Ring, Sky 1, Thursday

The recipe for a good story, as Julian Fellowes can tell you, is blindingly simple. Take one big house, throw in a dysfunctional family, add some financial worries, then garnish with a big question mark over the inheritance. The tale of Blenheim Palace has all that and more: a druggy son, a dukedom, and even a walk-on part for David Cameron. It knocks Downton into a cocked hat.

And so began The Aristocrats: Blenheim Palace, the first in a series of studies of Britain's premier toffs by the Bafta-winning documentary-maker, Patrick Forbes. Blenheim's current custodian, the 11th Duke of Marlborough, John Spencer-Churchill, has run the Oxfordshire estate for 40 years, and a good job he has done too. Despite having 187 rooms and 11,500 acres to maintain, Blenheim is profitable and in tip-top condition. Trouble is, Sunny, as he is known (short for one of his titles, Earl of Sunderland), is 86, and his son, the Marquess of Blandford, is the wastrel former coke addict who has been in prison three times. In 1994, Sunny made legal history by successfully disinheriting him, making relations somewhat tense.

Not surprisingly, the Spencer-Churchills aren't keen on publicity, so it was a coup for Forbes that they let him film for a year. His second triumph was finding a small scoop: Blandford has been clean for five years, and the Duke has reversed his decision to disinherit him. He will get the whole lot on his father's death though, like his father, he will have to report to a board of trustees.

The contrast between father and son could not have been better conceived by Chekhov. Sunny is of the same mould as the Queen: dutiful and proper, with a trim moustache, one who, in the manner of many who run big houses, spends his time noticing the little things that need to be done. His obsession is the verges, which must be neatly clipped. Jamie, on the other hand, is raddled and vague, a blundering hooray with half-baked ideas of grandeur. "What I'd really like to do is put in a giant fountain," he blathers. "Like the one Lord Wemyss has at Stanway: something that shoots 400 feet into the air, a ninth wonder of the world!"

Forbes spent seven months filming the Duke before he was granted access to his son. You can see why: despite making an effort not to make a fool of himself, Blandford can't help the odd gaffe; he reveals that he lobbied David Cameron for a grant towards a dam that needed rebuilding. At times, it was excruciating to watch – not just him, but because you could hear Forbes's weaselly questions, as he tried to coax Blandford into making a fresh blunder.

Still, for all the tinkling harpsichord music and slavering shots of Blenheim, Forbes's film shows that inheriting a Vanbrugh palace isn't as much fun as it sounds: that's one big albatross to have around your neck. As the family joke goes: the 1st Duke won the battle of Blenheim, the rest of the family is fighting it. Blandford would still clearly rather party than worry about lavatory blocks, and in that you can feel some sympathy for him. Some houses are just too big to live in, and according to Hugo Vickers, who knows about these things, seven out of 11 dukes have been depressed living there. You feel less sympathy (and some vertigo) when Blandford announces that he'd quite like to go into politics. It strikes me that running a big estate is rather similar to being an MP: glamorous from the outside, but the reality is a lot of admin and fixing blocked drains.

Fulfilling a mad ambition is what Freddie Flintoff has been doing since March. The ex-England cricketer decided, at 34, to become a professional boxer, and has spent eight months training for his fight on Friday. Like so many sports movies, From Lord's to the Ring followed a familiar arc from blind optimism through doubts to finally facing the big day. We even got the obligatory montage, fast-forwarding through months of gruelling training.

The question isn't so much if he's up to it physically, but if he can do it mentally. As his trainer, Barry McGuigan, wonders: "Is he too nice?" He certainly seems it, especially when talking about being bullied as a boy and the pain of seeing headlines like "Not bad for a fat lad" early on. Even if he is demolished on Friday, his reputation has been restored – as sport's most lovable rogue. He's funny, open, self-effacing and thoroughly likeable. And he's candid about his drinking too, which he's obviously had to give up. "If I don't have a drink for four and a half months, I'll be ready to punch someone", he quips. I know I wouldn't want to be in that ring on Friday.