Updated Sinclair coefficients for 2024 Olympiad

[owlcms]

Historically, a Canadian statistician named Roy Sinclair produced the coefficients that bear his name for every Olympiad.  Since his death, Marc Poretti has taken over the analysis.

You will find in the attachments the updated tables.

owlcms will incorporate the 2024 coefficients in its next release (4.34).  Because some federations use Sinclairs for various markers, the program will allow selecting between the 2020 Olympiad values (which is what has been used so far), and the new 2024 Coefficients.  Note that I will keep using the 2020 values for the Masters SMF and SMHF  until I get confirmation that they will switch.

Here is the text from Mr. Poretti.

Preface: As my last correspondence pertaining to the Sinclair Coefficients was with the past IWF president, I do not have the current president's email address and have taken an educated guess. I trust that if I do have the correct email address that the IWF Secretariat will forward this to the appropriate party or individual.

 

Dear Mohammed Jalood;

 

On behalf of Dr. Roy Sinclair's daughter Lori Sinclair, I am very pleased to once again be involved with updating and sending you the Sinclair Coefficients. I made the incorrect assumption that the Sinclair Coefficients were no longer required once the adoption of the ROBI system was introduced. Mr. Meltzer reached out to me at the beginning of 2022 requesting if I could update the Sinclair Coefficents for the 2021-24 time period which I was happy to oblige. Unfortunately life has a funny way of throwing a curveball and the change in bodyweight classes required additional rigour to ensure that the numbers accurately reflect the essence of what Dr. Roy Sinclair was aiming to achieve.

 

The standardization to 10 bodyweight classes for both males and females has been taken into account in the revised Sinclair Coefficients. I ran numerous calculations which I plotted and compared to historical data from previous periods, ultimately determining that the World Standard (WS) records that were assigned on November 1, 2018 skewed the data. As such I did not include the WS totals which produced much better results. With having used fewer data points to produce the Sinclair Coefficient in the past, I feel confident that these numbers are more reflective of the bodyweight classes that will ultimately be grown into.

 

Three PDF files have been produced and are available to be shared and distributed.

• 2021-Sinclair_Coefficients.pdf - provides a brief overview of the Sinclair Coefficients and how to calculate the Sinclair Total.
• 2021-2024.Female_SC_Chart.pdf - Sinclair Coefficient Reference Chart for Females
• 2021-2024.Male_SC_Chart.pdf - Sinclair Coefficient Reference Chart for Males

I will ensure that the numbers are updated going forward at the regular cadence that Dr. Roy Sinclair envisioned.

 

I did not include the in depth commentary on how the SC were derived for this period. It is a work in progress at this point in time. The previous version of the document (Sinclair_BW_Correction_Fromula_2017.pdf) is still relevant, just the input data (World Records and bodyweight categories) is different. If anyone is interested in the updated document, please let me know and I will forward the document once I have it completed.

 

Yours in sport,

 

Marc Poretti

ma...@poretti.ca

+1 (780) 920-6272