TV review: The Great British Bake-Off, BBC2

New Tricks, BBC1

Over the past five weeks I've surprised myself by becoming strangely obsessed with The Great British Bake-Off. On the surface, this isn't the sort of show I find it easy to get into. I have next to no interest in baking, loathing its fiddliness and reliance on precision and consistency, while the tone has always seemed insufferably twee.

And yet… there's something about the Bake-Off that's compelling. It's partially the competitors themselves – a likeable bunch of teachers, army wives and students with not a prima donna among them – and partially the fear that at any minute everything could all go horribly wrong.

In contrast to most reality shows that feature the sort of fame-obsessed lunatics you enjoy seeing fall flat on their faces, the contestants on GBBO are so nice that wishing ill-will on them seems almost against the spirit of the thing. For goodness' sake, these are people who instead of competing against one another dispense sensible, helpful advice, which surely contravenes some kind of reality television law.

There's also no denying that some of my fascination comes from just how alien this all is. As people announce that they feel sick with fear or are brought to tears by their toppling towers, it's hard not to shout: "Pull yourselves together, people, it's a cake, a gooey construction of flour and sugar, not the Eiffel Tower."

But it's precisely because they can't that the show works so well. This week saw our eight remaining contestants tackle tray bakes, tuiles and towers. Along the way, amiable English teacher Glenn attempted to scale down his sizeable ambitions, having one of his best weeks in the process, poor Frances of the punning designs saw everything collapse at just the wrong moment and wonderfully honest philosophy student Ruby announced: "I will not be defeated by a sodding French biscuit."

In the end, she survived to fight another day as not even a cleverly constructed Dalek tower could save Rob, who had earlier been damned for failing to maximise his talent. As to who will actually win: both cameras and judges clearly love Ruby, but my money is increasingly on Christine. She might not be as photogenic, but she's unflappable, good at the technical stuff and quietly competent each week.

Something about Tuesday nights clearly screams cosy to TV schedulers. Thus, after the Bake-Off, you could switch over to BBC2's sister channel for New Tricks, a show that still pulls in huge ratings in its 10th season despite looking increasingly ragged around the edges. As its star Amanda Redman remarked last year: "It's more bland now. The characters are not as anarchic as they used to be."

Certainly, the sense of companionship that once made New Tricks ideal, if undemanding family viewing has all but vanished, as indeed have most of the original cast. James Bolam left at the beginning of the ninth series, Alun Armstrong quit earlier this season and last night saw the final appearance of Redman's Pullman, leaving Dennis Waterman as the last survivor.

Replacements Denis Lawson and Nicholas Lyndhurst do their best to suggest they're having a good time, but there's no doubting that this drama has all but run its course. Even the appearance of the ghost of Jack Halford in last night's episode to dispense advice to the wavering Pullman ("You can't stay here for ever") served only to painfully recall the days when this show had a certain lightness of touch even if the plots rarely stayed in the mind.

In the US, long-running procedural shows such as CSI and Law & Order are often rejuvenated by the arrival of new casts. In the case of New Tricks, however, I can't help feeling it would have been better to put this old dog down.