One of the uncountable records Eddy Merckx holds is his success to win four consecutive grand tours in a row. No one ever has won all the three grand tours in a year, but a double was no more impossible since Fausto Coppi won Tour de France and Giro d’Italia in the same year for the first time in 1949. To win four consecutive grand tours means a cyclist have to win two in one and another two in the next season. Also, all the three gand tours have to be involved in this record.
As well known among cycling fans, for decades, Vuelta a Espana was held in the spring, right before Giro d’Italia. (The first autumn edition was held in 1995.) Tour de France was, of course, the peak of the cycling season, and most of the top riders choose usually Giro d’Italia as their second grand tour participation.
In 1972, Eddy Merckx won both Giro d’Italia and Tour de France, with this result he was then a 4-time Tour de France (1969, 1970, 1971, 1972) and 3-time Giro d’Italia (1968, 1970, 1972) winner.
Next year he decided to ride Vuelta for the first and only time in his career, and right after also Giro d’Italia.
At the Vuelta, the inevitable happened: Eddy Merckx, at the peak of his career, won the Spanish grand tour at his first attempt. Then he went to repeat his overall victory from previous year at the Giro d’Italia.
Thus he started his winning streak in the early summer in 1972 (Giro d’Italia was held between 21 May and 11 June), won the Tour de France in next month, then triumphed at Vuelta a Espana in the spring of 1973 and few weeks later he stood on the top of the podium at Giro d’Italia again.
But he skipped Tour de France that year.