🚴Rules & Play

Because of drafting. A rider sheltered behind others spends up to 30 percent less energy than the one on the front, so a leader who saves that energy all day can attack when it matters most. Teammates, called domestiques, shield their leader from the wind, fetch food and bottles, chase down rivals, set a punishing tempo on the climbs, and pace him back after a puncture. A leader with a strong, disciplined team is protected from crashes, crosswinds and attacks until the decisive moment. This is why Grand Tours are often won by the best-supported rider rather than simply the strongest, and why team budgets are spent building depth around a single captain.

The three Grand Tours are three-week national stage races. The Tour de France, held in July, is the biggest and most prestigious, with iconic Alpine and Pyrenean climbs and a yellow leader's jersey. The Giro d'Italia, in May, is known for its unpredictable, often snow-affected mountain routes and a pink jersey, and is considered the most romantic and adventurous. The Vuelta a Espana, in late summer, favours explosive, short mountain stages with brutally steep climbs and a red jersey. Each covers roughly 3,500 kilometres over 21 stages and awards the overall win to the rider with the lowest cumulative time. Winning all three in a career is a rare distinction.

The Monuments are the five oldest and most prestigious one-day Classics, each a career-defining prize. They are Milan-San Remo, the longest at nearly 300 kilometres, held in March; the Tour of Flanders, decided on short, steep cobbled climbs in Belgium; Paris-Roubaix, the brutal Hell of the North run over cobblestone farm roads; Liege-Bastogne-Liege, the oldest, a hilly test known as La Doyenne; and Il Lombardia, the autumn race of the falling leaves through the hills around Lake Como. Winning a Monument ranks alongside a Grand Tour stage or a World title, and only a handful of riders in history have won all five.

A great deal, which is why it governs every tactic in the sport. Air resistance is by far the biggest force a cyclist fights at racing speed, and sitting directly behind another rider in their slipstream can cut the power required by roughly 25 to 40 percent, depending on speed and how sheltered the position is. Deep in a large peloton the saving is even greater. This single fact explains why a solo attacker rarely holds off an organised chase, why sprinters conserve energy until the final metres, and why a rider caught alone in a crosswind is quickly dropped. Managing when to shelter and when to spend energy is the essence of race craft.

In a Grand Tour, several competitions run at once, each marked by a jersey. The overall leader on cumulative time wears the leader's jersey, yellow at the Tour, pink at the Giro, red at the Vuelta. The points classification, the green jersey at the Tour, rewards consistent high finishes and suits sprinters. The mountains classification, the polka-dot jersey at the Tour, goes to the rider who collects the most points atop categorised climbs. The white jersey marks the best young rider, under 26. A rider can chase more than one at a time, and the rainbow jersey, seen year-round, denotes the reigning World Champion in that discipline.

The near-unanimous answer is Eddy Merckx of Belgium, nicknamed the Cannibal for his refusal to leave any race for his rivals. Between 1965 and 1978 he won a record 525 races, including 11 Grand Tours, three World titles and 19 Monuments, dominating sprints, mountains, time trials and one-day Classics alike, a range no rider has matched. Historic greats like Fausto Coppi, Jacques Anquetil and Bernard Hinault, each a five-time or multiple Grand Tour winner, follow him. The one modern rider whose trajectory could eventually challenge Merckx is Tadej Pogacar, who has already won multiple Tours, a Giro and World titles while also dominating the Monuments in a way not seen since Merckx himself.