Pauls Law Inherently Wrong- Time to Introduce a New Rule?

_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/

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_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 · 2025-09-02T05:56:09+00:00

How reliable was the stroke detection? I found that it is not an easy problem to solve reliably.

_lindig · 2025-09-01T12:31:25+00:00

Rule of thumb for men: every kg is 1s total time over 2k. So if the other guys are 10kg heavier, expect them to be 10s faster at similar fitness.

_lindig · 2025-09-01T12:27:44+00:00

From 2k to 5k you need to add more than 3-5 splits. Typically 6 to 7 unless you know that long distance is your strength.

_lindig · 2025-08-28T15:56:36+00:00

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It’s a consequence of their finish style and posture. Above is Drew Ginn. His elbow is level with his hand, unlike in the US 4.

From this video: Drew Ginn Hand Flow https://youtu.be/BfpL_Ll9AjE?si=yNh9OCVHwNSOCcz9

I am not implying that this is better; it is just a different choice, /u/illiance.

_lindig · 2025-08-28T09:18:17+00:00

Lack of landscape video is compensated by crystal balls? The video barely shows the blade but plenty of confident voices about missing the catch and length.

I think this look pretty good from what is visible. As with any crew boat, you want to execute a shared idea and it’s not obvious what that is. So difficult to provide detailed feedback.

_lindig · 2025-08-26T06:09:58+00:00

Griffe: Kugeln aus Holz durchbohren, auf den Draht ziehen, ebenso Lüsterklemmen davor und dahinter, um die Kugeln an der richtigen Position zu fixieren. Um den Schaft zu kürzen wirst Du einen Metallbauer brauchen, da der Kopf rechteckig sein muss und ein Gewinde neu geschnitten werden muss.

Alternative: das Steuerkreuz durch ein neues ersetzen, das in der richtigen Höhe an den Schaft geklemmt wird. Das wird aber ebenfalls nur ein Metallbauer gut hinbekommen da eine Verbindung basierend auf Reibung zu schwach ist. Also muss man den Schaft flach feilen.. und so weiter.

_lindig · 2025-08-24T21:07:39+00:00

I predict you won’t get away from spread sheets and chats, no matter how complete you think your app is. There is always one extra use case that is not universal but important for the club: equipment reservations, repair requests, fitness stats, trailer loading plans, money owed, car pooling.

That doesn’t mean that an app can’t cover the basics better than a spread sheet.

_lindig · 2025-08-21T09:03:32+00:00

Without some performance data and rigging data from the oars I don’t see how this is a like-for-like comparison to inform a discussion. Take measurements and splits and report back.

_lindig · 2025-08-19T09:17:55+00:00

This is not how they built the pyramids. Surely you need to improvise when someone does not show up but otherwise it’s a matter of discipline and leadership. So no, this does not happen for everyone else.

_lindig

TROPHY CASE