How many days a player need to spend with the club so his potential can be fully converted to skill. Also does there are any other parameter that bottleneck the skill for the staff. Also what is the ceiling for the skill level of the staff?

3 seasons in your team to get the best grade, which is his potential. The maximum is 90. You can reach it with training, but you need to be level 10.

Frank Lampard: How many days a player need to spend with the club so his potential can be fully converted to skill. Also does there are any other parameter that bottleneck the skill for the staff. Also what is the ceiling for the skill level of the staff?

168 days

Sun's: 168 days

No 156 days for 100% Of competence