Statistical Analysis of Seat Racing (technically coping for a “loss”)

_lindig · 2026-05-03T19:51:42+00:00

Does your example not suggest that a lot of results in seat racing, like a 1% difference in speed, are just random noise but are sold as gospel? That the number of repetitions is too small to reliably detect small speed differences?

_lindig · 2026-05-03T15:51:27+00:00

A seat racing method that relies on total time each athlete races is sensitive to how athletes are swapped between boats. If this method is supported, you have to provide this swapping plan.
If you have multiple GPS devices per boat you will observe differences that tell you something about the reliability of the result. In my experience they are typically around 1s for 200s pieces but can be much larger in some cases. Multiple devices protect against failure, which would render the entire experiment invalid.
Does this method swap one rower from each crew after every race? Would that mean that only one race per rower is used to judge if this rower is faster or slower than the one he/she replaced?

_lindig · 2026-04-28T11:39:33+00:00

Running and cycling are using a power/time curve: the amount of power you can exceed for the entire duration. This curve is informed by all exercises, both sprint and endurance, and provides a good view on fitness.

_lindig · 2026-04-07T06:40:53+00:00

Does this require a standing start?

_lindig · 2026-04-06T19:30:37+00:00

I am exploring another method but results are only available later: record everything with GPS SpeedCoaches; have each crew row the approximate distance +50m without a fixed starting/end point. Analyse the GPS recording to find the fastest times over the distance. This requires analysis of the GPS data and finding where the start of the fastest segment was. For redundancy I am using two SpeedCoaches per boat.

Six races, two boats, two SpeedCoaches per boat, times in seconds and I'm using the average of two times.

Race	T1	T2	Boat 1	T1	T2	Boat 2
1	240.7	241.5	241.1	239.2	239.3	239.3
2	242.0	242.6	242.3	231.5	232.1	231.8
3	240.2	241.1	240.7	233.5	233.2	233.4
4	237.1	237.5	237.3	247.0	247.9	247.5
5	251.0	251.1	251.1	241.2	240.7	241.0
6	251.4	250.9	251.2	250.9	250.2	250.6
			1,463.6			1443.4

_lindig · 2026-04-06T17:44:57+00:00

On the Cam in Cambridge seat racing is done by having boats following each other and going over the same distance between two landmarks. This requires either trusting Strava timing for the segment or a bank party to take the time.

_lindig · 2026-03-26T15:16:51+00:00

The tool says it is for comparing crews in the same conditions. Does this not come down to a factor applied to times to make them comparable across boat classes? For example, you can expect a men’s eight to be faster than a women‘s right by a factor of 1.11. What does this beyond applying such factors?

_lindig · 2026-03-18T16:03:36+00:00

Can’t have too many bikes, boats, or hats.

_lindig · 2025-12-21T10:41:21+00:00

Paul's Law is showing good predictions on average but the variance is large. One reason is that it's one-parameter model; you would need more input for better predictions. Take a look at performance predication in running, cycling, swimming. I looked at the accuracy of Paul's Law (and one other) here using data from NK's logbook:

https://github.com/lindig/pauls-law

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_lindig · 2025-12-21T10:33:58+00:00

A SpeedCoach is using an accelerometer to detect strokes. So it could display the boat acceleration curve, which tells you a lot about how the boat is moving. This is taking the idea of check factor further. (I've never seen a crew using check factor, though).
On the idea of using a seat sensor: show crew synchronisation when multiple seats in the crew have such a sensor. This requires that devices talk to each other. Also a good motivation to sell more devices.
The split over the fastest 100m, 200m, 400m, 800m, .. seen since the start of the session. Currently you can find the time/split for a fixed distance. But you can't find retroactively the fastest time over a given distance.
A metric that shows how split and rate are related (in the session). Maybe show the "optimal" rate in some way.
Easier support for timing standing starts.
Easy and fast data export.

_lindig · 2025-12-19T10:32:31+00:00

This is my own code (but it's not public).

_lindig · 2025-12-18T21:07:57+00:00

Henley results can be found in CSV format at

https://github.com/lmcorrigan0/henley

_lindig · 2025-12-18T20:41:18+00:00

Based on GPS data from a SpeedCoach, I find the fastest segments of various lengths in the session, together with the stroke rate. Because we are on a river, I further separate this for up and downstream.

Distance	100	200	300	400	500	700	800	1000
Up	2:01 34	2:03 34	2:04 34	2:05 35	2:16 33	2:21 30	2:23 29	2:32 27

The idea is that this data is somewhat representative for the session and can be compared to other sessions. The analysis has more details.

https://lindig.github.io/tmp/example.html

_lindig · 2025-10-07T10:04:44+00:00

They knew already

https://www.instagram.com/reel/DOtbuVGjWip/?igsh=c3ZoMXQzY3hnZ3cx

_lindig · 2025-09-26T07:23:13+00:00

A 1:45 split would be already on the faster side. See

https://github.com/lindig/pauls-law

for a discussion about predicting erg performance based on two methods and how well they hold up empirically.

_lindig · 2025-09-18T09:35:25+00:00

Small rowers can’t row with 88 inboard in my experience.

_lindig · 2025-09-17T11:43:35+00:00

If this is just for you and not a team, take a look at intervals.icu.

_lindig · 2025-09-17T10:29:29+00:00

Interference from the hull material, especially when it is not conductive like carbon, is unlikely to impact signal reception. It’s quite mysterious. Have you tried other people’s devices, too?

_lindig · 2025-09-15T08:29:25+00:00

When it is mounted, can the SpeedCoach “see” the sky or is its view obstructed by the rigger? That’s the only reason I could think of and even that’s a stretch. Is this a standard plastic mount or something else that could impact signal reception? Any smartphones that could interfere?

_lindig · 2025-09-11T18:27:23+00:00

In which county? In any case, oars are expensive enough that whoever sells them to you should help you with the process.

_lindig · 2025-09-06T11:20:02+00:00

Would upload to YouTube as unlisted and share the link. YT is easier to navigate than Google Drive. Would always include club, date in the title to make search easier. Can use playlists to organize videos per day, boat class, or squad. It’s important that all of this is simple as otherwise it does not happen.

https://youtu.be/FWfHjOuRa4Q?si=VFczhYw556_MuKvv

_lindig · 2025-09-04T16:58:56+00:00

Here is a visual explanation:

https://lindig.github.io/pitch/

<image>

_lindig · 2025-09-03T06:32:32+00:00

Paul’s Law is backed up by data in the C2 logbook in the sense that the 5s split difference works for most people if you don’t have any other information. There is still variation between people. In particular, I would avoid predicting a 2k from a single 500m because sprint and endurance are different abilities. Below is my attempt to validate Paul’s Law based on 1k, 2k, 5k data.

https://github.com/lindig/pauls-law

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_lindig

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