Frenchman Warren Barguil has a lead of 49 points over yesterday's stage winner Primoz Roglic.

There are a maximum 52 points on offer today - including a bumper 40 for winning at the summit finish of the Col d'Izoard.

Then there are only six points for three category three climbs tomorrow and that's your lot.

Expect Barguil to be on the attack to sew up the polka dot jersey today. And does Roglic even have enough to challenge after yesterday's triumph?

It's looking likely that with Barguil and Matthews, Team Sunweb will be heading home with two of the four jerseys.

Image source, Getty Images

Just had a shot of Steve Cummings in the break - hanging on the back of the break, but in the break all the same.

I think this stage might be too tough for the British rider to challenge for victory, perhaps he's just so good at getting in breaks he ends up there by default.

Look out for him trying to catch out the sprinters tomorrow on stage 19.

It's unusual for a Tour de France champion to go through the whole race without a stage victory.

And it looks like Chris Froome doesn't want to break with tradition this year.

Speaking to LeTour.com this morning, Froome said: "It's an iconic mountain. It's going to be the decider. Izoard is the Mont Ventoux of this Tour de France. If there's an opportunity, I'll go for the stage. With Mikel Landa, we have a good chance to play. And if everything goes well today, it will be a big step forward."

However, if he doesn't win today, Froome could also target Saturday's time trial.

Image source, Reuters

Talking of the Izoard...

Our intrepid (and now sleep-deprived) BeSpoke team out at the Tour de France have put together this cracking video of the legendary climb that ends in a desert.

It's well worth a watch - click the link below or you can watch it here.

You'll also be able to listen to live commentary from Simon Brotherton and Rob Hayles by clicking the tab at the top of this page from 14:30 BST.

BBC Sport app users may have to click 'view more' to see this content.

A reminder of where the race is heading today - a summit finish on the Col d'Izoard.

This brutal climb - 14.1km at 7.3% average gradient - has featured plenty of times on the Tour but never before as a summit finish.

Image source, Le Tour

The front group has swollen to 54 riders now and they have a lead of 3'52'' on the yellow jersey group.

Sky, Bora and LottoNL-Jumbo are the only three teams not to be represented in the front group.

Sky won't be too bothered about that for now - unless one of Froome's rivals bridges to a team-mate up the road later.

LottoNL-Jumbo have got their big stage win after Roglic's victory yesterday.

Bora do have Sagan's stage three win but that break is perhaps a missed opportunity for them.

Image source, Reuters

Britain's Simon Yates looked to be cruising to the best young rider's white jersey - for the fastest rider under 26 years old - and therefore keeping it in the family after twin brother Adam won it last year.

A tough day yesterday, though, has seen his lead to South Africa's Louis Meintjes fall to two minutes 28 seconds.

Yates will need to mark Meintjes to ensure he does not lose too much - or preferably any - time today.

Fortunately, Yates is a better time triallist than Meintjes, having finished over 30 seconds faster in the opening 14km time trial in Dusseldorf, so should better him in Saturday's 22.5km stage.

But anything can happen in a time trial at the end of a three-week grand tour.

Image source, Getty Images

I'll try to pick out some names to watch out for in that leading group of 51.

Bauke Mollema, Tony Gallopin, Lilian Calmejane, Thomas de Gendt, Thomas Voeckler, Pierre Rolland, Sylvain Chavanel...

The list could go on and on. Plenty of impressive riders with decent pedigree in riding successful breakaways.

Will be fascinating to see if they can stay away and how it will break up later.

Image source, Getty Images

Those four out front have duly been caught by the huge group behind.

There are now 51 riders up the road, some 2'20'' ahead of the peloton.

The best-placed on general classification up there is Brice Feillu, who is over 33 minutes down on Chris Froome.

So no need for the peloton to chase.

Image source, Reuters

It's not just the yellow jersey battle to look out for today - most of the other jerseys could be effectively settled by the end of play...

After Marcel Kittel's abandonment yesterday, Michael Matthews now has a 160-point lead over Andre Greipel in the green jersey points classification.

There are technically 200 points left on offer in this Tour, but neither Matthews nor Greipel will win today's stage or the time trial, effectively leaving 160 points out there.

Just one more point for Matthews - perhaps at the intermediate sprint today - and the Australian only needs to stay upright to pull on green in Paris.

Image source, Getty Images

Andre Greipel is on the attack...

A bit too little too late to challenge Michael Matthews for the green jersey, I'm afraid.

He's 160 points behind the Aussie and there are only 160 points in reality on offer so he'd need Matthews to get zero points over the next four days.

More on these races within the race to follow...

There's not so much a breakaway group as a whole separate peloton out in front of the main peloton.

There are four riders out at the very front by themselves, though.

Alessandro de Marchi (BMC), Thomas de Gendt (Lotto Soudal), Elie Gesbet (Fortuneo-Oscaro) and Lilian Calmejane (Direct Energie) have a gap of 12 seconds or so.

The usual suspects Thomas Voeckler and Thomas de Gendt are at it again, trying to break clear up front.

A huge group of 30 or so riders are off the front of the peloton, but riders are bridging gaps all the time.

It'll be a while before this settles down.

A bit of a delay beyond the neutral zone before the flag came down.

But here it goes - and there go plenty of early attacks, trying to establish a breakaway.

Image source, Getty Images

A reminder of where things stand on the general classification...

1. Chris Froome (GB/Team Sky) 73hrs 27mins 26secs
2. Rigoberto Uran (Col/Cannondale-Drapac) +27secs
3. Romain Bardet (Fra/AG2R La Mondiale) Same time
4. Fabio Aru (Ita/Astana) +53secs
5. Mikel Landa (Spa/Team Sky) +1min 24secs
6. Daniel Martin (Ire/Quick-Step Floors) +2mins 37secs
7. Simon Yates (GB/Orica-Scott) +4mins 07secs
8. Louis Meintjes (SA/UAE Team Emirates) +6mins 35secs
9. Alberto Contador (Spa/Trek-Segafredo) +7mins 45secs
10. Warren Barguil (Fra/Team Sunweb) +8mins 52secs

It's a belter.

179.5km from Briancon to Izoard, taking in a category three and a category one climb before that monster 'hors categorie' summit finish on the Col d'Izoard.

Plenty of races within the race today - not least the glory of becoming the first rider to win a Tour stage that finishes on the Izoard.

Will Chris Froome want to win it in yellow?

The peloton have just rolled out from Briancon. Stay tuned.

Image source, Le Tour

A mammoth day at the Tour de France is matched by a mammoth climb to end stage 18.

No Tour stage has never finished on top of the legendary Col d'Izoard - until today.

The final day in the mountains is also, realistically, the final day for Chris Froome's rivals to rip the yellow jersey away from him, with the British rider expected to take more time on them in Saturday's time trial.

Expect tension. Expect attacks. Expect pain.

Here we go...