Dumoulin won the Giro in 2017 – his big breakthrough as a Grand Tour rider – and returned this year to finish second behind Chris Froome. He went on to finish second at the Tour de France, and many had expected him to focus squarely on July and France in 2019.
However, after weighing up the routes for both races, which were revealed in October, the decision has been made to make the Giro the primary objective of the season once again.
"After weeks of talking about it, we finally decided the main focus will be the Giro d'Italia in 2019. We had the Tour de France for a long time in our head but the Giro is such a nice course this year. I really love Italy, I love the course, and I love the race. Afterwards is very likely that I will do the Tour de France for GC, just like this year, but it's still undecided," Dumoulin said in a video message announcing his plans on Saturday.
The 2019 Giro d'Italia contains no fewer than three individual time trials, totalling 58.5km against the clock. The race opens with an 8.2km time trial in Bologna, before a crucial 34.7km stage 9 time trial in San Marino, and then a 15.6km test on the final day to decide the maglia rosa. All three are far from flat, but none are truly mountainous enough to count against Dumoulin, who thrives on the hillier parcours and won the 2017 world title at the top of a steep climb in Bergen.
The 2019 Tour de France, by contrast, only features one individual time trial – a 27km course in Pau on stage 13 – along with a 28km team time trial on stage 2.
"We looked at both routes and we made our calculations. On paper – and in cycling you should always expect the unexpected – our chances would be better in the Giro than the Tour," Iwan Spekenbrink told Cyclingnews.
The routes were known by the end of October but Sunweb have only set about finalising race programmes this week as they’ve gathered in Calpe, Spain, for a pre-season training camp. In the meantime, their decision has been informed by data analytics software built for the team by KPMG, which allows them to input the detailed characteristics of each stage of each route, along with past performance data, in order to produce a model of the likely outcome.
"The data does not decide for us, but it challenges us," said Spekenbrink. "Is our gut feeling right? Or does data show something different? In this case all the data analytics that we did with our people and our data-partner KPMG confirmed our gut feeling."
Dumoulin will make the Giro d'Italia the focal point of his Grand Tour plans in 2019, but he hasn't ruled out going for the Tour de France as well.
This year he was second in both, suggesting that the famous 'double' – last achieved by Marco Pantani in 1998 – was in reach, even if this year was something of an anomaly with an extra week between the two, owing to the football World Cup.
For the time being, however, the team are only setting their sights as far as the end of May.
"He'll do the Giro and after that we'll look at the Tour," Spekenbrink said. "The whole preparation we have more or less under control. It's three weeks at high intensity, and anything can happen, so we'll make a full analysis then calculate if it is possible or not to do the Tour de France. At the moment we don't have that under control, so it makes no sense to speculate now.
"We'll go full gas for the Giro, then we'll reassess and see where we are. If we believe it's reasonably possible to do well in the Tour then we'll go. If the Giro has cost too much then we won't."