This post analyzes the importance of the different legs in a long-distance triathlon and how many of the leaders in T1 and T2 end up winning the race. For the 2017 season, there are 74 data points (40 different race courses: 7 Challenge races, 26 Ironman races with male and female fields, 6 single-gender Ironman races, and Embrun). There are links to all the results mentioned, so feel free to explore some of the amazing 2017 races!
Best Swim (also Leading in T1): 19%
In 2017, the swim leaders were able to win slightly more races (14 out of 74 or 19%) than in previous years (2016: 14%, 2015: 17%). Athletes that lead in T1 and go on to win the race usually lead “wire-to-wire”. As in previous years, there was only one instance where an athlete “lost” the lead on the bike and then re-claimed it on the run. This year it was Clemente Alonso-McKernan who had the fastest swim at IM Sweden but then was more than seven minutes behind Cameron Wurf in T2 before putting ten minutes into Cam to win the race.
Not very many athletes are able to have the best times in all three legs, in 2017 there were four: Daniela Ryf (winning IM South Africa), Timothy O’Donnell (winning IM Boulder), Jan Frodeno (winning IM Austria) and Laurel Wassner (winning IM Taiwan). It is much more common to win a race with “a balanced performance”, without having the fastest time in any leg: In 2016 there were 11 races, this season there were 13.
Of course there are a lot of athletes that can win the race even when they are not part of “the front group” after the swim. However, 80% of all winners in Ironman-distance races are less than 4:55 behind in T1. It is quite rare to see athletes winning a race that are more than ten minutes behind after the swim (in 2016 there were only 4 races or 5%). The biggest T1-deficit was overcome by Jodie Robertson who was 13:39 behind Lauren Brandon, the T1 leader at IM Texas. On the male side, Timothy Van Houtem made up 12:21 at Challenge Madrid. The slowest swims by IM winners were a 1:10:23 by Lisa Roberts at Challenge Madrid and Lukas Krämer who won Challenge Venice with a 1:01:33 swim.
Best Bike: 57%
As the bike is the longest leg in Ironman, of course it does have a large influence on the outcome. This was even more evident in 2017 (42 of 74 races or 57%) than in previous years (2016: 49%; 2015: 54%).
Similar to the swim, 80% of the winners are within 4 minutes (3:51 to be exact) of the fastest bike leg in a race. Only six athletes in 2017 were able to “afford” losing more than ten minutes on the run to the fastest bike riders. Lisa Roberts lost 17:22 to Rachel McBride at IM Cozumel, and Patrick Lange lost 15:59 to Cam Wurf at IM Hawaii.
Leading in T2: 58%
“Leading in T2” continues to be the best indicator for winning a race. This year’s share of 58% (43 out of 74 races) is similar to previous years (2016: 50%; 2015: 57%).
Even with a T2 lead, you still have to run pretty well to win the race, even if we saw two 2017 winners lose 20 minutes on the run – but those were super-bikers Andy Starykowicz (losing 20:33 to 17th place finisher Josh Terwood when winning IM Louisville) and Cam Wurf (losing 19:22 at IM Wales to Andrej Vistica who ended up in fourth place). As for most of the “80% gaps”, T2 leaders that go on to win the race lose less than five minutes on the run.
Best Run: 49%
Having the fastest run is another strong winning indicator. This year’s number (36 out of 74 or 49%) is almost the same as previously (2016: 49%; 2015: 40%). 80% of the winners were able to post times within 4:56 of the fastest run splits. Most of the slow run times by winners were caused by tough climatic conditions: The three slowest marathon times by winners were Laurel Wassner’s 3:49 at IM Taiwan, Verena Walter’s 3:25 at Challenge Taiwan and Diana Riesler’s 3:19 at IM Malaysia – all in tough conditions and all three within four minutes of the best run splits. (Laurel even had the fastest female run split at IM Taiwan.)
There were some pretty large gaps that winners were able to make up on the run: Lisa Roberts made up 24:46 at IM Cozumel (followed by Rachel Joyce 12:24 at IM Mont Tremblant), on the male side Matt Hanson won at IM Texas even being 15:10 behind in T2, another big gap was Patrick Lange’s 10:55 deficit in Kona. Typically the gap has to be much smaller, 80% of winners are within 5:14 of the leaders in T2.