Do Semi-Finals Matter? A Look at the Data

Do Semi-finals matter?

Semi-finals in swimming are a controversial topic. There are basically three schools of thought on the topic.

One school is that they are a waste of time and energy, they make meets longer, and they don’t really change the final outcomes.

Another points out that maybe the “challenge” we’re trying to create and the “best of” standard is “who is the best in the third of three rounds, spread over two days”. This could be coupled with “the sessions can’t become any more compact because of doubles anyway.”

A third school of thought is less-stated and more-often implied, but basically would be the ‘null’ state: that semi-finals are an important step toward determining the final 8 field with the top swimmers racing as close to head-to-head as possible for that opportunity.

Other race sports often use semi-finals. In some sports, like track & field or rowing, the top performers in the heats get a free pass to finals, whereas the next-best group might have to compete in a repechage for a chance at the medals.

But swimming, frankly, doesn’t have as much parity of many of those sports, and it would be a pretty radical change (one that wouldn’t go over well) to force some swimmers to race an extra round and not others – which could push bigger gaps into the idea of parity.

Some of this stuff cannot be solved with data, but to frame the conversation, I asked SwimSwam’s Daniel Takata, who runs the @swimmingstats Instagram account, to look at how many medalists (and gold medalists) finished outside of the top 8 in prelims.

Acknowledged: applying data from meets where there are semi-finals is not a perfect surrogate for meets where there aren’t semi-finals. Swimmers would approach races differently. That makes the analysis incomplete-by-definition, but not without value.

Doubly acknowledged: medals aren’t the only goal of swim meets.

Since semi-finals in the 50m, 100m, and 200m events were re-introduced at the 2000 Summer Olympics, there have been 1,391 medals distributed in those events at the Olympic Games and World Aquatics Championships.

Only 120 of those 1,391 medals (8.6%) placed outside of the top 8 in prelims.

If we drill down to gold medals (463 since 2000), 20 finished outside of the top 8 in prelims (4.3%).

This means that even with an incentive structure that doesn’t require a full-effort prelims swim from a top performer (threading that needle is a valuable skill on its own), switching from a semi-finals system to a straight prelims-finals system has some impact, but not immense impact.

At more recent meets, here are the medal numbers:

  • 2021 Olympics: 1/60 medals (only Japan’s Yui Ohashi in the women’s 200 IM, which she won)
  • 2022 Worlds: 7/79 (8.9%)
  • 2023 Worlds: 8/79 (10.1%)
  • 2024 Worlds: 6/78 (7.7%)

This 7-10% range seems to be pretty consistent across the board.

In other words: the data is inconclusive. This number is neither low enough to fully wave it away nor high enough to declare a definitive sorting value to the semi-finals.

Because of the nature of swimming, it would be impractical (if not impossible) to test the influence of semi-finals on prelims effort in any empirical way.

My take? I’d love it if we could cut out semi-finals to find a way to trim the meet back to a 7 or 8 day event. I think that anything shorter than that winds up with some unintended consequences. Maybe leaving semi-finals in for 50m and 100m races, but dropping them for 200m races, would be the compromise, because the gaps from the medalists to the non-finalists in 200 meter races would be significant.

The data actually shows that more swimmers finish outside of the top 8 in prelims in the 200 meter races and go on to medal than in the 50 and 100 meter races, but my hypothesis is that this is just because swimmers have more room to play with in the 200 meter races.

Since 2000

  • 50m events: 27/352 medals = 7.7%
  • 100m events: 33/363 = 7.1%
  • 200m events: 60/576 = 10.4%

But amid the constant tug-of-war whereas we debate whether swim meets should be viewed as spectator events or base-development events, dropping semi-finals could dissuade some countries from investing as much in the sport (it’s easier to spend tax dollars on sports when citizens can cheer for athletes in prime time). It also adds some storylines to the game, gives fans more things to be fans about.

At a minimum, it would allow athletes to compete on the biggest stages the same way that they compete the rest of the year (it’s very rare even for Olympic Trials to employ semi-finals).

Whatever the system, the athletes and coaches and training would inevitably adjust, and in a few decades, the thing that once felt new would again become norm.

In This Story

Leave a Reply

Notify of

oldest most voted
Inline Feedbacks
View all comments
16 days ago

To make it simple..Get rid of SEMIS. Even being a swim nerd, after day 7 at trials, I was tired! And I was just watching it on TV. And for those that care, without semis, maybe 50s might find a spot?

1 month ago

I have been a long-term fully financial member of the Hate, Loathe and Despise Semis association. The sport moved along quite well without them in the 80s & 90s; go fast or miss out is tough but its also very clear as to what you have to do.

Having said that; I’m sufficient a pragmatist to realise that the Fat Cats of the sport aren’t going to give way automatically so would put forward a proposal with some degree of flexibility.

  • Semis for all 200m events – Gone
  • For 50/100m events; top 4 (not stuck on numbers, could make it 2 fastest) automatically qualify for final
  • The next fastest 4 finishers can either “sit” on their prelims time OR
… Read more »

Teknik Informatika
1 month ago

What is the implication of this school of thought?

Gardner Howland
1 month ago

In 2000 Julia Stowers and Kim Black were 17th and 19th after prelims of the 200 free. Dara Torres and Kalyn Keller scratched. Julia and Kim dropped time and finished 7th and 8th in semis. The next night they were 4th and 6th, both earning a spot on the Olympic Team. I would guess that they both found the semi finals to be beneficial!

1 month ago

There definitely should be semis in the 50 free and in all of the 100 meter races: between the number of entrants and the depth of the fields in these events, it makes sense to have three rounds of racing, and these races are short enough that they should not be causing significant fatigue.
As for 200 meter races, perhaps we could think out-of-the-box on this one: clearly there are some races of this length (e.g. the women’s 200 free) where depth and numbers warrant three rounds of racing, while others (e.g. the women’s 200 fly field at the 2021 Olympics) at times have not. So perhaps whether or not there are semis for a given 200 should be… Read more »

Kudzai Makova
1 month ago

Swimmers with multiple event schedules will almost always manage their energy across prelims to finals. In sessions where they have doubles, it’s incredibly important to do the bare minimum to advance and peak in the finals. Same can be said for track and field. Usain Bolt would literally jog in his 100m heat to advance. For 200m events, the Semis can be scratched (faster heats to make top 8) with finals the following day would be a great format…

This Guy
1 month ago

I do not like Semis.

The goal is to find out who is the fastest in the world in a particular event, not who can manage the schedule of multiple rounds of competition. At the very least 200s should not have semis.

I want to see the very best go after it as hard as possible with everything on the line and not have that thought of potentially saving some effort for a semi-final of another event that they will have to take into consideration.

Give me speed! Give me world records! I don’t want Meet Management to be such a large conversation in this sport.

Last edited 1 month ago by This Guy
Steve Nolan
Reply to  This Guy
1 month ago

just have time trials then

1 month ago

Swimming does it wrong. If you do semis then the top 2 or 3 from each semi should be guaranteed the final. But that’s not what they do. They still take the top 8 regardless. In this structure it’s an unnecessary and tiring round of swimming. Go to prelim/final format.

I’ve stated my opinion on this before, go to prelim/final and give us a chance to see the best in multiple events. Under current makeup swimming semis are an abject failure.

About Braden Keith

Braden Keith

Braden Keith is the Editor-in-Chief and a co-founder/co-owner of He first got his feet wet by building The Swimmers' Circle beginning in January 2010, and now comes to SwimSwam to use that experience and help build a new leader in the sport of swimming. Aside from his life on the InterWet, …

Read More »