Numpty >> dinsdag juli 2 - 23:06, Bewerkt woensdag februari 12 - 15:26

Following on from an earlier question I thought it would be a useful reference to document how players age with regard to their Ageing Factor.

The decrease is non-linear, and I believe that there are 4 separate stages that each have a different rate of decline. 

1. The Ageing Factor remains constant at 100% up until the age of around 21 years 18 weeks.

2. From 21y18w it declines at a rate of 1% every 30 weeks until the age of around 26 years (possibly a little earlier). 

3. From age 26 to 30 it declines at a rate of 1% every 21-22 weeks. 

4. From age 30 onwards it declines at a rate of 1% every 12-13 weeks, which is roughly 4% per year. This is why outfield players drop off quite quickly once they reach 30 years of age.

Since the reported Age Factor is a rounded value, how do you know exactly what value to use if you're doing a calculation? So here is a quick reference that will give a more accurate percentage:

Edit

The correct formula has now been posted below, but this table may still be useful as a quick reference. I have also amended any minor errors. 

Age Factor - Age

• 100%  - 21y18w
• 99.00% - 21y48w
• 98.00% - 22y26w
• 97.00% - 23y04w
• 96.00% - 23y34w
• 95.00% - 24y12w
• 94.00% - 24y42w
• 93.00% - 25y20w
• 92.03% - 25y49w 
• 91.69% - 25y50w 
• 91.00% - 26y13w
• 89.98% - 26y35w
• 89.02% - 27y04w
• 88.00% - 27y26w
• 86.98% - 27y48w
• 86.02% - 28y17w
• 85.00% - 28y39w
• 83.98% - 29y09w
• 83.02% - 29y30w
• 82.05% - 29y51w
• 82.20% - 30y00w
• 82.04% - 30y02w
• 81.00% - 30y15w
• 80.04% - 30y27w
• 79.00% - 30y40w
• 78.04% - 31y00w
• 77.00% - 31y13w
• 76.04% - 31y25w
• 75.00% - 31y38w
• 74.04% - 31y50w 
• 73.00% - 32y11w
• 72.04% - 32y23w
• 71.00% - 32y36w
• 70.04% - 32y48w

For other values use the formula below. 

Numpty >> woensdag juli 3 - 08:04

Good shout! I'll also see if I can produce a formula at some point. 

Numpty >> woensdag februari 12 - 14:30, Bewerkt woensdag februari 12 - 15:43

So, I've finally managed to produce what I believe is the correct formula for the Ageing Factor. 

1. The Ageing Factor remains constant at 100% up until the age of 21 years 18 weeks.

2. Starting at 21y19w it declines at a rate of 1% every 30 weeks until the age of 25 years 49 weeks. Which is 1.7333% per season.

• AF = 1 - 0.001*(x/3) = where x is age in weeks greater than 21y18w

3. There is a noncontiguous change at age 25y50w, when the players ages by the equivalent of about 10 weeks.

4. From age 25y50w the AF declines at a rate of 3% every 65 weeks, which is 0.6% every 13 weeks, 0.0461538% per week, or 2.40% per season. This continues until the age of 29 years 51 weeks. 

• AF = 0.916 - 0.03*(y/65) - where y is age in weeks greater than 26y00w

(Formula is based on 91.6% at age 26y00w for simplicity. Also use with the previous 2 weeks where the increment becomes positive.)

5. There is a further noncontiguous change at age 30 years 0 weeks, where the player gets younger by the equivalent of 3-4 weeks. Yes, younger!

6. From age 30 until 47 years 18 weeks the AF declines from 82.2% at a rate of 2% every 25 weeks, which is 0.08% per week and 4.16% per season.

• AF = 0.822 - 0.0008*z - where z is age in weeks greater than 30y00w

7. The Ageing Factor remains constant at 10.0% from the age of 47 years 19 weeks onwards.

(Eddie's formula, mentioned above, is very close but is not 100% accurate.)

I want to acknowledge the contribution of Sazz, who helped provide me with data for analysis.

Kupus >> woensdag februari 12 - 14:33

@Numpy

Finally, what took you so long :)

Numpty >> woensdag februari 12 - 14:35

I am getting older. I only work at 10% :)

Numpty >> zondag oktober 15 - 16:42

Link to thread discussing how the Age Factor affects the decline rate of Blocking and Keepers. 

https://rockingsoccer.com/en/soccer/forum/home-en/680?topic=69882