25 days ago, 12 fresh housemates entered the Big Brother House, each of them cuffed to another of their number.

Two-by-two they wandered meekly in, and the eagle-eyed amongst you may have noticed something a bit peculiar. Of each pair, only one remains for the final. No two that entered the compound together survives to see the final.

How on earth has this happened? What the devil is occurring? 

We're taking an important look at each twosome to see what the devil went on.

Evander and Luisa

When he entered the House, Evander was quickly lauded as the big name, a four-time heavyweight champion of the world. Luisa, by contrast, was a finalist from The Apprentice.  So how did he end up leaving first, while she made it all the way to the finale?!

Well, firstly Luisa has been at the centre of so much action in the House. She’s had blazing rows with Lionel, Jim and Dappy, while also sharing romantic moments with Dappy and Jasmine. This is the stuff CBB fans love! Evander, on the other hand, didn’t say very much at all, and when he did say something, it didn’t always boost his popularity. Luisa has upset the apple-cart on several occasions, but has always survived to tell the tale.

Dappy and Liz

Almost entirely diametrically opposed in terms of their outlook on life (did you see Dappy's face when Liz spoke about how naughty Rihanna had been?), Dappy and Liz went their different ways once the cuffs were off. Dappy's been something of a livewire, naked pool-jumping, diving on beds and throwing himself into the refreshments whenever they've been served. Liz, on the other hand, kept herself to herself and rarely made a spectacle of herself. Maybe viewers crave activity and found Liz's wise and silent head a little bit hard on their patience?

Lee and Casey

Trying to break this relationship down would take an entire dissertation; suffice to say Lee and Casey gave us plenty of opportunity to take sides over the course of their time in the House. Both went in were prepared to give a new relationship a shot but, as time went on, Lee made a few fatal mistakes, occasionally forgetting the cameras were on him. You might speculate that Lee's flirtation with Jasmine, return to Casey (and refusal to acknowledge why all of that might look a bit out of line) probably sealed his fate, leaving Casey sitting pretty for the final.

Ollie and Lionel

This pairing is slightly different from the rest, in that Ollie and Lionel were thick as thieves and, on that first evening in the bungalow, even looked like a Before and After picture of the same man. Or an elderly entertainer and his shiny ventriloquist puppet. Where Ollie has been accused of fence-sitting and over-diplomacy, Lionel was as outspoken as any housemate CBB in history has seen. Perhaps it's an age thing? At 82, Lionel clearly didn't care what anybody thought of him – and he didn't think anything of dropping the F-bomb at any opportunity. Some viewers might have taken offence when Blair turned the air blue. We didn't, but they might have.

Jim and Linda

These two were worlds apart, with a complex relationship that overshadowed the whole House. We've not been party to what went on between them before they entered as cuff-chums, but whatever it was didn't get dealt with amicably within. As with Lee and Casey, despite long periods of peace they had enormous fall-outs where we were inevitably forced to pick a team. Team Jim won out by quite a way, so it's Jim who heads for the final with Linda out of the picture.

Jasmine and Sam

Here we had a shy girl from Essex, famous for her girl next door simplicity and English Rose appeal, cuffed to a tabloid favourite wild child from across the pond. Who was going to appeal to British viewers more? The one who let it all hang out on launch night and had toilet-sessions in a love triangle or the one who flirted so mildly with Ollie that we were all forced to read more into it than was probably actually happening? You guessed it. It was finalist Sam. Fair play to the girl from TOWIE.

We'd love to tell you that this weird split down the middle, marked by the chains of those handcuffs was all part of the plan, but we're pretty sure it wasn't. Back here at BB HQ we've lost the launch night blueprints, so it's probably all coincidence. Anyhow, the point is you've picked your finalists, and a right rum bunch they are too. Congratulations and kudos, viewers. You've set us up for one of the finest ever finales, filled with fantastic finalists and we simply can't thank you enough.