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The Individual Medley is a 200/400 yard event in swimming that consists of all four strokes. It is swum in the order of butterfly, backstroke, breaststroke, and freestyle, and has been a staple of every well-rounded swimmer’s repertoire. Those who compete in the event choose their distance based on their strengths, with sprinters preferring to swim the 200 IM and distance swimmers the 400 IM. Since there are very few pure IM swimmers, most people swimming the IM event likely specialize in a single stroke; the question is, which stroke specialists do the best in IM? We looked at NCAA D1 times for the last 10 years to determine how impactful each stroke was for the fastest swimmers.
For the 200 IM, we used only swimmers who had gone under 1:43.00 at some point. Additionally, we used each swimmer’s career best swim. What we observed was that butterfly was the most impactful stroke towards predicting 200 IM success, with backstroke and breaststroke relatively close in terms of how much they mattered. Interestingly, freestyle meant almost nothing in terms of how fast one’s 200 IM was.
One thing to note, however, is that the two fastest swimmers in 200 IM history, Caeleb Dressel and Andrew Seliskar, are almost statistical outliers in terms of how fast they are at the 200 IM. Dressel has a 1:38.13, while Seliskar has a 1:38.14; the five next best times range from 1:39.35 to 1:39.63. When we take out Dressel (the world record holder in the 100 fly) and Seliskar, backstroke actually becomes slightly more impactful than butterfly, with the impact of breaststroke dropping as well.
Interestingly enough, at this point, freestyle means almost nothing to the 200 IM, as a r2 value of 0.00576 means that less than 6% of a 200 IM swimmer’s success is a result of their 50 free. While freestyle is by no means unimportant, this low impact rating is likely a result of nearly everyone in college being good at the 50 and 100 free, as they are core components on NCAA relays.
For the 200 IM short course, the freestyle leg is probably the least impactful leg. Working on free likely won’t help your 200 IM time as much as working on fly or back since most people split roughly the same on free, regardless of their proficiency at the stroke. Breaststroke can also be good to work on, especially if your breaststroke severely lags behind the rest of your strokes. Overall, butterfliers and backstrokers will probably see the most success in the 200 IM.
Now, the 400 IM. The 400 IM is a terrifying distance event, and probably the hardest event in all of swimming; it requires a 100 of each stroke, all of which are meant to be sprinted. The difference between trying pretty hard and trying so hard you feel like your eyeballs are going to fall out is probably around 10 seconds, meaning that any extra effort you put in, especially in the back half, is going to pay off tenfold.
We once again analyzed the fastest NCAA D1 swimmers, this time for the 400 IM, using a cutoff of 3:43.00 (these are arbitrary cutoffs, I just didn’t want to manually input that many swimmers). We observed that fly still remained the most important stroke and free the least. However, in the 400 IM, free was almost 4 times as important as the 200 IM. Additionally, almost 95% of swimmers went faster on their second 50 free than their first 50, a technique known as “negative splitting”.
Coaches have long preached the importance of “negative splitting” in the 400 IM, or going faster in your second 50 than your first 50 within each 100. No negative splits were done during the butterfly leg because of the dive on the first 50, but almost every swimmer had a negative split in the 100 back and 100 free. Almost nobody had a negative split on the 100 breast.
We also found that the most crucial 50 within the whole 400 IM was the second 50 breast; at this point, most people are very tired and slowing down, but don’t have that pressure to finish fast from freestyle yet. Those who could mentally handle powering through the second 50 breast were the fastest 400 IM swimmers.
Overall, for the 400 IM short course, all the strokes are much more equal; if you are a swimmer looking to improve at the 400 IM, you should get really good at negative splitting backstroke and freestyle. Additionally, you should try over swimming breaststroke by doing 300 or 400 repeats to get a feel for sprinting the second 50 of breaststroke even when exhausted. Finally, don’t be scared to go out fast in the 100 fly; almost every swimmer was within four seconds of their best 100 fly time for the first 100 of the 400 IM.
Link to data used