Race Analysis: How Quah Zheng Wen Controlled the Men’s 100m Butterfly to Win SEA Games Gold 2025, Thailand

Credit: Straits Times

The Men’s 100m Butterfly final at the 2025 SEA Games delivered a high-quality, tightly contested race — and it was Zheng Wen Quah who executed best when it mattered most. Stopping the clock at 52.25, Quah secured gold for Singapore with a swim built on control, experience, and intelligent race management, adding another major SEA Games title to his career. Quah opened decisively, turning at the 50m mark in 24.26 — the fastest first-half split in the field — immediately taking command and forcing Indonesia’s Joe Aditya Wijaya Kurniawan and Thailand’s Surasit Thongdeang into chase mode for the entire back 50.

On the return lap, as fatigue set in across the pool, Quah held his form and rhythm, closing in 27.99 to absorb the late pressure from a fast-closing pack and touch first. While the margins were narrow on the scoreboard, the pattern of the race was clear: Quah controlled the race from the front and never truly relinquished that control, using his underwaters, stroke efficiency, and composure under fatigue to protect the lead he built early.

Swim speed: how fast he moved

The race opens with a world-class burst: Start to Breakout (15.0 m) in 5.21 s at 2.88 m/s, the fastest water he sees all race and the clear velocity ceiling for the day. From there, speed settles to 2.06 m/s between Breakout and 25 m and 1.82 m/s over L1: 25–50 m, giving him a stable first-50 profile after the explosive launch and setting up that 24.26 opening split at halfway.

After the turn, he carries 2.50 m/s through Turn 1 Breakout (13.0 m), then navigates the fatigue-heavy third quarter at 1.49 m/s from Breakout to 75 m, his slowest segment by speed but one where length is preserved. The final L2: 75–100 m lifts slightly to 1.65 m/s over 15.20 s, roughly 42.7% down from his 2.88 m/s peak, but still quick enough to convert the early speed and tactical control into a gold-medal touch with form intact.

Stroke rate: how fast he cycled

Across the full 100 m, Quah averages 27.8 spm, and the segment pattern shows intention rather than random fluctuation. After the no-stroke Start to Breakout phase, he moves to 57.5 spm from Breakout to 25 m, then softens slightly to 54.4 spm on L1: 25–50 m as he shifts from pure acceleration into controlled cruising to close out the first length.

On the second 50 m, stroke rate stays impressively tight: 56.6 spm from Breakout to 75 m and 56.0 spm across L2: 75–100 m. That shallow, controlled adjustment in tempo — instead of a sharp spike or collapse — is a major reason his 27.99 closing split looks composed and why he can hold connection while others are straining to change gears.

Distance per stroke: how well he held water

Efficiency is where this 100 m fly shows its championship quality. From Breakout to 25 m, he sits at 2.00 m per stroke at 57.5 spm, using higher rate with full length to lock in early pace straight after the underwater. Then the stroke shifts into race mode: L1: 25–50 m holds 1.92 m per stroke at 54.4 spm, a classic blend of long strokes and moderated tempo that supports his aggressive but controlled first-50 strategy.

On the back half, the metrics confirm that technique holds together despite rising fatigue. From Breakout to 75 m, he maintains 2.00 m per stroke at 56.6 spm while travelling at 1.49 m/s, preserving distance per stroke through the hardest part of the race. In the closing L2: 75–100 m, distance per stroke compresses only to 1.79 m at 56.0 spm, indicating a controlled shortening rather than a technical breakdown and matching how stable his closing speed appears on the clock.

Why this race works for Quah

Taken together, the numbers describe a 100 m butterfly brilliantly structured for high-pressure racing. An elite 2.88 m/s start and 28.0 m of underwater at 2.69 m/s give him early command without overextending; a mid-race band around 1.82–2.06 m/s with DPS near 1.92–2.00 m shows genuine efficiency on the front half; and a 1.65 m/s closing segment with almost unchanged stroke rate shows he can absorb fatigue without losing form. For Singapore, that combination of speed, stroke quality, and race intelligence is exactly what you want from a proven butterfly leader — and for Quah Zheng Wen, it provides a robust blueprint to chase even faster times off the same race model.

How can we help?

SwimInsights is designed to unpack races like this in the same way for any competitive swimmer — from segment-by-segment speed, stroke rate and distance per stroke, to underwater usage and overall efficiency patterns. If you would like a similar race report for your own performance or for your swimmers, you can submit race details and video through SwimInsights to receive a structured breakdown, clear visuals, and coach-ready insights tailored to your event.

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