With six days in the can at the 2018 Tour de France, Team Sky is sitting at the top of the list of overall contenders. They have a rider three seconds behind Greg Van Avermaet, who has been kind enough to keep their Yellow Jersey warm for the race’s opening week. This scenario is par for the course for the British squad and barely merits a mention in a first week Tour de France piece. However, there is a major wrinkle in the plan this year. The leader sitting in pole position with sparkling form is former Sky domestique, Geraint Thomas, while the four-time Tour de France champion Chris Froome sits close to a minute down in 14th overall.

While we saw Thomas ahead of Froome during the Tour’s first week last year, it was by a mere twelve seconds, and the moment the road tipped skyward, Thomas stumbled and ceded the overall lead to Froome. But as of stage 6 in 2018, Thomas hasn’t put a foot wrong and currently sits second overall, a full minute (technically 59 seconds) ahead of Froome. Most importantly, he outperformed the former champion on the first big climbing test. The stage 6 finish on the slopes of the Mur-de-Bretagne saw Thomas finish five seconds in front of Froome. The eye-test revealed an even bigger gulf in form than the final results let on. Thomas looked incredibly strong and appeared to even be a legitimate contender for the stage, while Froome dangled off the back. The Welshman looked appears to be on the form of his life, while Froome appeared fatigued from his recent Giro d’Italia victory.

While the climb is much shorter and more explosive than the high alpine slopes where the race will be decided, the Mur has proven to be a reliable bellwether of climbing performance later in the race. In the Mur’s past two appearances, the eventual race winner has been present in the front group of finishers. Froome’s absence in the lead group could be a sign of things to come later in the race.

The gulf between the two riders even has the potential to widen before the Tour hits its first real mountain stage when the peloton hits the cobbles of Paris-Roubaix during Stage 9 on Sunday. Thomas was once a legitimate classics contender, and while he has slimmed down and lost raw power since those days, he still posses deft bike handling and an ability to read the treacherous cobblestones. It stands to reason that Thomas will be able to pull out even more time over the more traditional GC contenders who have little-to-no experience on the brutal cobblestones. While anything could happen on Sunday’s stage, it wouldn’t be a surprise to see Thomas head into the first rest day with a sizeable advantage. This scenario would wreak havoc on Sky’s team dynamics and Froome’s ability to mount a long-range attack similar to his coupe on stage 19 of the Giro d’Italia. A lot was made of Movistar’s decision to bring three leaders to the 2018 edition, but not enough attention was paid to the leadership tussle that was set up when Sky designated Froome and Thomas co-leaders.

This co-leadership situation raises a number of complications and theoretical questions. For example, what if Froome had suffered misfortune like Tom Dumoulin and Romain Bardet at the base of stage 6’s finishing climb? What would the team have done? Would Thomas feel compelled, or be forced, to sit up and wait for his teammate, or would Sky be true to their “co-leader” word and let Thomas ride away from a four-time champion while he waited for a wheel change?

Many have been saying Froome comes into form later in grand tour’s and the early setup is nothing to worry about. There is only one issue with this argument, it isn’t true. While he came back with a stunning late-race comeback in the 2018 Giro, he traditionally pulls out his winning margins in the first 10 days of a race.

In 2016, 2015, and 2013, Froome took a significant chunk of his winning margin in the first 10 stages. In 2013, Froome took 40% of his winning margin to Quintana on the first mountaintop finish of Ax 3 Domaines, on Stage 8. In 2015, at La Pierre-Saint-Martin, Froome took 88% of his eventual winning margin to Quintana on Stage 10.

2016 deviated slightly from this template. Froome won the first mountain stage into Luchon, a shocking downhill victory, netting 23 seconds. This gap was only roughly 9% of his winning margin and the first big gaps had to wait until individual time trial on Stage 13. In 2017, he used the steep slopes of La Planche des Belles Filles on stage 5, and a slight time bonus on stage 9 to carve out an 18-second lead by the stage 10 mark, which turned out to be 33% of his final margin.

While Thomas is obviously a massively talented cyclist with a mind-boggling set of skills, and looked on incredible form at June’s Dauphine Libere, he has an abysmal track record in three-week grand tours. He’s never stood on a podium at a grand tour, and his biggest result on the road is the overall win at the aforementioned Dauphine Libere. It is incredibly risky to suppress Froome’s chances of pulling back time in the name of backing an unproven Thomas for victory. Even if Froome has free reign to ride his own race in the mountains, he certainly won’t have access to the team’s vast firepower to wind up a long-range attack like we witnessed at the Giro.

The co-leadership situation with Thomas, at one point an abstract way to repay a loyal teammate for years of service, is starting to look like a major liability to Froome’s potential, and record-tying, fifth Tour de France title. It is too early to draw any definitive conclusions, but Sky could have a legitimate leadership controversy by the time the race heads into the Pyrénées during the third week.