Stage 4 of the Tour de France will throw the cobbles of Paris-Roubaix into the mix, favouring 2015 spring champions Degenkolb and Kristoff... as well as any others who can turn the situation to their advantage.

The 223.5 km Franco-Belgian trek from Seraing to Cambrai will be the longest stage in the Tour, but there is much more to it than its length. 11.5 kilometres of cobblestones await within the final 150 kilometres, distributed in six sectors classics specialists will remember from Paris–Roubaix. Recent history shows that the Tour's cobblestone stages will separate the wheat from the chaff, sometimes cruelly, as Fränk Schleck (crashed out of the race in 2010) and Alberto Contador (almost 2′ lost in 2014) can attest. At the end of the day, there will be losers in Cambrai, but also winners, like Nibali last year.

There are cyclists who enjoy riding on cobblestones, though, and some of them are quite good at it. Their hunting season is usually ephemeral but bountiful enough for true specialists to shine. The 2015 season has witnessed the rise of two prodigies set to dominate the cobblestones for years: Alexander Kristoff, who capped an unprecedented Flemish streak with his triumph at the Tour of Flanders, and John Degenkolb, the second German Paris–Roubaix champion, after Josef Fischer won the inaugural edition in 1896.

His victories in San Remo and Roubaix have catapulted the Giant-Alpecin sprinter towards the top of the pecking order. The raw power he has displayed for several years now, combined with his improved tactical acumen and handling skills, put him in the pole position to claim his first Tour stage win here… unless he triumphs two days earlier in Zeeland! His Norwegian rival, who is also taking part in his third Tour de France, already got a couple of wins under his belt in Saint-Étienne and Nîmes last year. Although slightly off the pace in Roubaix (10th), Kristoff has what it takes to grab the extraordinary stage to Cambrai.

Degenkolb and Kristoff's classics dominance will not scare the rest of the pack. 34-year-old Fabian Cancellara may be flying the flag for an earlier generation, but he has still got some fight in him and his experience on the cobblestones could well play in his favour on July 7. Potential successors also have talent in spades. Peter Sagan (6th in Roubaix in 2014 and 4th on the Arenberg stage), Zdeněk Štybar and others have yet to claim their first major triumph on the cobblestones, but their curricula are already pretty impressive.

The pretenders to the overall crown will not be mere spectators either. If he can muster the strength to do so, Vincenzo Nibali will not hesitate to strike at his rivals like he did last year, when he discovered this hostile terrain. The Italian can even count on Lars Boom to pull it off, but Chris Froome, who in 2014 did not even make it to the first sector, will have more than enough firepower to fight back thanks to teammates such as Geraint Thomas and Ian Stannard. It remains to be seen how Spanish-speaking riders, usually out of their element on the cobblestones, will fare: quite a challenge for Alberto Contador, Nairo Quintana, Joaquim Rodríguez…