Administrator wrote: In calculation you have to also predict: 1. some injuries - player doesn't get training points when injured 2. after age 27 player is starting to loose skills (some decreasing) Beginner must search for players with high team work, when coaches and training hall are fully upgraded, then team work looses some importance.

Sorry to call you on this but do skills start degrading at 27 or is it just training?
From the FAQ:
3. How does players age influence the training?
The amount of training points players receive each training cycle steadily decreases after the age of 27 and after the players reach 31 they don't receive any training points at all. This is because they need all the training just to sustain their skills. After the age of 31 the players also start to lose points in their physical skills. See the list below for more info.
- Players aged 16 to 27 train normal and lose no points due to their age.
- Players that are 28 years old lose 25% of their training.
- Players that are 29 years old lose 50% of their training.
- Players that are 30 years old lose 75% of their training.
- Players that are 31 years old get no training points. They also lose from 10 to 15 points on Speed, Strength, Agility and Stamina each training cycle.
- Players that are 32 years old get no training points. They also lose from 16 to 20 points on Speed, Strength, Agility and Stamina each training cycle.
- Players that are 33 years old and above get no training points. They also lose from 21 to 25 points on Speed, Strength, Agility and Stamina each training cycle.
NOTE: No player skill can go below 12 because of his age.

Don't be sorry, I made lapsus linguae. Good work, my mistake was not a test.

Instead of training points I wrote skills. Skills start to decrease with age 31 and if you noticed the word "decrease" is differently colored in training report.

In average with fully upgraded coaches and training hall you can count on new skill level in two weeks:
(regular 10pt + coaches 20pt + hall 20pt + teamwork +-2pt random)-10% focus on skill - occasionally injury (no points at all). With age 28 this number is decreased by 25% each year to year 31 as stated in FAQ.