In this week’s Talking Tactics I’m breaking down exactly how and where Chris Horner defeated reigning Giro champion Vincenzo Nibali to become the oldest grand tour winner in history five weeks short of his 42nd birthday.

The Vuelta has a habit of producing closely fought battles for overall victory, particularly in recent years. Horner’s winning margin of 37 seconds doesn’t even make it into the top ten – Eric Caritoux won in 1984 by just six seconds – with four of the previous ten editions decided by no more than 30.

How the race was won

The 2013 race was close throughout, with the top two not entirely out of reach of Alejandro Valverde and Joaquim Rodriguez until the final trio of summit finishes on stages 18 to 20. The tight ebb-and-flow of the race was illustrated by the fact that both Horner and Nibali enjoyed three separate stints in the red jersey, with the American only seizing control for the final time on stage 19. Indeed, the pair were never separated by more than 50 seconds at any point, with Horner’s maximum lead being a mere three seconds until the summit of the Angliru on the penultimate day.

In terms of head-to-head results, the time gap fluctuated constantly. Of the 21 stages, Nibali gained time on five days versus seven for Horner. The chart below shows how small most of the gains were – six of the 12 swings were of ten seconds or less, with only two being larger than Horner’s final 37-second margin (stages 10 and 11).

The graphic also clearly indicates that Nibali gradually fell away as the race progressed: three of his five gains came in the opening ten-day stint – and none in the final week – whereas he lost time on each of the final four summit finishes.

Overall, as the table below shows, Horner ‘won’ the first and – most importantly – the final week of the race, turning a 28-second deficit into a 37-second advantage after the final rest day. (Discounting the individual time trial, he would have won the middle week too.)

The American’s margin of victory would have been even greater without the two time trials, where Nibali gained 1:39 on him. It was in the mountains where he held a consistent edge over the Sicilian, as he made gains worth 2:36 on seven of the 11 summit finishes – the biggest being 52 seconds on stage ten and 34 on stage 20 – and recorded two wins. Nibali, by contrast, failed to win an individual stage and only twice bested Horner in the mountains, gaining just 14 seconds in the process. Nibali’s net loss in the mountains was 2:22. This was where Horner won the race – and if the Angliru was where the coffin lid was nailed shut, the vital seconds gained on the final climb of the first week also proved critical in offsetting the losses which he knew were inevitable in the ITT which immediately followed it.

Finally, it’s worth noting that nearly half of Horner’s winning margin came from end-of-stage time bonuses. Victories on stages three and ten plus a second on stage 20 and third on stage 14 meant he accrued an additional 30 seconds versus just 12 for Nibali from his two second places (stages ten and 14). Without the bonuses Horner would still have won, but by only 19 seconds, which would have been the sixth smallest winning margin in Vuelta history.

It was a close-run thing in the end, but the Vuelta again underlined its reputation as being a race that gives pure climbers such as Horner the edge, whereas the Giro and Tour require more all-round skills including strength against the clock.