4/4 Relay Splits: Why Consistent Flying-Start PBs Are Key to World Records

In an article published on SwimSwam two weeks ago, Kim Youngbeom outlined his belief that the South Korean quartet can break the men’s 4×200 freestyle world record this summer.

To do so, the swimmers would need to deliver the race of their lives. Summing the fastest relay splits of the four swimmers—based on their best flying starts—yields a total of 6:58.92, just 0.37 seconds shy of the United States’ world record set at the 2009 World Championships.

The question is: how realistic is that? How often do we see all four swimmers in a relay hit personal bests?

For this analysis, we pulled data from 2000 onward—covering Olympic Games and World Aquatics Championships—and considered only relay finals. In total, there were 982 relays where each swimmer’s best flat-start time prior to the event could be identified.

Relay Splits vs Flat-Start PBs:

• All 4 faster: 70 (7.1%)

• 3 faster: 333 (33.9%)

• 2 faster: 317 (32.3%)

• 1 faster: 193 (19.7%)

• 0 faster: 69 (7.0%)

Getting all four swimmers to outperform their flat-start PBs is rare—but when it happens, medals tend to follow:

Placements in those 70 “4-for-4” cases:

• 1st: 17 (24%)

• 2nd: 13 (19%)

• 3rd: 15 (21%)

• 4th: 9 (13%)

• 5th/6th: 12 (18%)

• 7th/8th: 4 (6%)

64% of those 4-for-4 relays ended up on the podium.

However, since relay splits are flying starts (except for the leadoff), it’s more accurate to compare splits to flat starts minus 0.3 seconds. This adjustment accounts for the average advantage of a relay start. The 0.3-second figure is conservative—flying starts often give swimmers a 0.3 to 0.5-second edge.

Adjusted Relay Split Comparison (Flat Start – 0.3s):

• 4/4 faster: 39 (4.0%)

• 3/4: 189 (19.2%)

• 2/4: 293 (29.8%)

• 1/4: 314 (32.0%)

• 0/4: 147 (15.0%)

It’s even rarer to go 4-for-4 under adjusted times.

Events Where 4-for-4 Occurred (Adjusted Times):

Freestyle relays, especially 4×100, dominate these occurrences.

Placements in Those 39 Relays:

• 1st: 11 (28%)

• 2nd: 8 (21%)

• 3rd: 8 (21%)

• 4th: 6 (15%)

• 5th: 3 (8%)

• 6th: 2 (5%)

• 7th: 1 (3%)

• 8th: 0

70% of relays with 4-for-4 adjusted PBs landed on the podium.

Notable 4-for-4 Examples:

China Women’s 4×200 Free – Tokyo 2021 (WR: 7:40.33)
Beat Australia’s 2019 mark by 1.17s. Split improvements vs flat-start PBs:

• Junxuan Yang: 1:54.37 (1:54.57)

• Muhan Tang: 1:55.00 (1:57.29)

• Yufei Zhang: 1:55.66 (1:57.22)

• Bingjie Li: 1:55.30 (1:56.64)
  Total improvement: 5.39s (avg: 1.35s)

Australia Women’s 4×200 Free – Beijing 2008 (WR: 7:44.31)
Total PB improvement: 5.38s (avg: 1.34s)

• Stephanie Rice: 1:56.60 (1:57.31)

• Bronte Barratt: 1:56.58 (1:56.60)

• Kylie Palmer: 1:55.22 (1:58.79)

• Linda Mackenzie: 1:55.91 (1:56.99)

USA Women’s 4×200 Free – Worlds 2003
Total improvement: 4.30s

• Lindsay Benko: 1:57.41 (1:58.56)

• Rachel Komisarz: 1:59.34 (2:01.13)

• Rhiannon Jeffrey: 1:59.14 (1:59.76)

• Diana Munz: 1:59.81 (2:00.55)

USA Men’s 4×100 Free – Beijing 2008
Total improvement: 3.39s

• Phelps: 47.51 (47.92)

• Weber-Gale: 47.02 (47.78)

• Jones: 47.65 (48.35)

• Lezak: 46.06 (47.58)

Other notable 4-for-4 wins include:

• China women’s medley (2009, +5.18s)

• China women’s 4×200 free (2009, +4.28s)

• USA women’s 4×200 free (2004, +3.30s)

• Netherlands women’s 4×100 free (2009, +3.11s)

• Russia men’s 4×100 free (2003, +3.03s)

• Australia men’s 4×100 free (2000, +2.65s)

What About 3-for-4?

Still strong. Here’s the breakdown by event:

Placements:

• 1st: 37 (20%)

• 2nd: 32 (17%)

• 3rd: 31 (16%)

• 4th: 21 (11%)

• 5th: 27 (14%)

• 6th: 21 (11%)

• 7th: 11 (6%)

• 8th: 9 (5%)

For South Korea to break the men’s 4×200 free world record, all four swimmers must deliver extraordinary performances—something historically rare. But when it happens, history tends to follow.

And isn’t that what greatness is all about?