Back when the ASP (now WSL) opted in favor of making Round 4 a non-elimination round,



Round 4’s gnar-factor, or lack thereof



If you tuned in to watch a CT Round 4 heat this year and saw someone riding a wave, chances were about 8% that you would see an excellent ride (score between 8.0 and 10.0, as defined by the WSL’s judging scale). However, had that been a Round 5 or Quarterfinal heat, the odds would’ve been approximately 9% and 10%, respectively. It’s important to emphasize that those are the same surfers in all 3 rounds. Surfers that win in Round 4 jump straight to Quarterfinals, while those that lose have to surf Round 5.



It would be easy to accept better surfer performance in Quarterfinals since those are technically Round 4’s best surfers, but when Round 4’s losing surfers also go on to perform better in Round 5, questions must be asked. It would seem the WSL inherited a format that makes the same surfers perform worst by subtracting the elimination factor.



Same amount of waves per surfer, yet fewer excellent rides



So far this year, average wave count per heat has been 1.5x higher in Round 4 than in both Round 5 and Quarterfinals. It makes sense, if there are more surfers in the water more waves will be caught, provided there are enough to go around. However, after adjusting for the number of surfers in each heat, it was found that on average each catches 6 waves per heat in these three rounds.



This serves to show that each surfer has had about the same number of opportunities to post big scores, yet the odds of that actually happening on an individual-wave basis have been lower in non-elimination Round 4.





There is no more motivation to do big, risky, radical maneuvers (the ones that lead to excellent scores) in Round 4 than there is in any other round.

To further analyze the effect of the non-elimination factor, we can also compare individual CT surfers’ top performing rounds. When doing this we found that only 12% of world tour surfers hold non-elimination Round 4 as their top-performing round, while the same is true for 22% in elimination Round 5, almost twice as many.In fact, top CT aerialists such as Filipe Toledo, John John Florence, Gabriel Medina and Josh Kerr have all performed their highest average heat scores this year in elimination rounds (Finals, Quarterfinals, Round 5 and Round 3, respectively).Let’s take a closer look at what’s going on. Round 4’s top average score belongs to Miguel Pupo, coming in at 17.23; however, he has only made it to this round once this year, making his result too susceptible to factors such as swell, judging criteria, etc. Instead, lets focus on the next top Round 4 surfer, Filipe Toledo, since he’s made it to this round 3 times so far this year. Filipe’s average Round 4 heat score is 16.38, which comes as no surprise considering his high-flying antics. Surely, it must be thanks to the stress-free, radical-maneuver friendly environment that Round 4 provides, right? Wrong. Filipe has actually performed better in elimination rounds such as Round 3, Semifinals and Finals, with the last round being his top performing round.There is no more motivation to do big, risky, radical maneuvers (the ones that lead to excellent scores) in Round 4 than there is in any other round. If anything, there is actually less, since either way you won't be buying a return ticket home that night. Add in the injury factor that radical maneuvers bring to the table and there’s evenmotivation. Essentially, when a surfer goes for a radical maneuver such as a huge air or a death-defying elevator-drop floater he is risking injury and potentially the rest of his season. So why not save it for when the stakes are actually high?Loss aversion, a theory first demonstrated by Amos Tversky and Daniel Kahneman, is arguably playing a role at tour events. According to Wikipedia, in economics and decision theory, loss aversion refers to people’s tendency to strongly prefer avoiding losses to acquiring gains, with most studies finding the former to be as much as twice as psychologically powerful than the latter.Not all non-elimination rounds were created equal, though. The need for non-elimination Round 1 actually makes sense, since it's a good way to avoid the negative effects that surfers being jet-lagged, unacquainted with the break or "rusty" can have on the competition’s final outcome, but by the 4th round it's pretty safe to assume that nobody's still jet-lagged.In an attempt to measure the “elimination factor” (or “loss aversion factor”), we can go back and use the probability that a surfer on a random Round 4 wave would produce an excellent score. We look for excellent scores because that’s where the “show” is. Those are the waves that make up the bulk of the highlight reels, get shared by fans on social networks, and increase surfing’s appeal as a spectator sport.First, it‘s necessary to adjust for the fact that, theoretically, Round 3’s best surfers are in the Quarterfinals and therefore will possibly inflate the round’s wave scores. We can easily do this by averaging out the probabilities from both Round 5 and Quarterfinals, giving us an average probability of 9.5% that a surfer on a random wave in Round 5 or Quarterfinals will post an excellent score, as opposed to 8% in Round 4. Since surfer quality has already been adjusted for, and assuming wind/wave conditions are equal, it could be argued that the 1.5% difference is a “loss aversion premium” that elimination rounds have over non-elimination rounds.If the WSL were to, hypothetically, modify the current format established by the ASP, Round 4 could be a good place to start. Eliminating the losing surfer from each Round 4 heat could potentially introduce and leverage a “loss aversion premium” in a round already packed with waves! Additionally, such a move would eliminate the need for Round 5, since the eight remaining surfers would go directly to Quarterfinals, allowing for a shorter, more versatile event format that could increase the percentage of heats that are run in ideal conditions.It would seem there is a trade-off between quality and quantity, with the former possibly holding the key to enhancing spectator experience. When viewers tune into CT events surely it’s the high of watching the best surfers in the world performing at their very best that they’re after, so why not optimize the format for