Football Manager 2021

here's a few tips that will help you a lot in order to get this achievement, and will not require editor or unlockables

- delegate all responsibilities to other staff
- in matches use commentary only, no replays etc
- in preferences > advanced > set continue game timeout to instant
- after every match > go to home > my profile > go on holiday until next match

using these methods it will vastly speed up processing in-between matches, you may have a few things to deal with in your inbox now and again but most of your duties will be picking your team which can be easily done via quick pick button

you don't necessarily need to pick a good team to get this, but if you are aiming to get all the achievements, i recommend picking a good team so you can get this one too

The fastest way is to enable the "Become unsackable" in the in-game editor and just go on holiday for 20 years.

I recommend starting in Iceland or Singapore as the seasons are shorter.

If you aren't using the editor, the best option is to pick a mid-sized team in any league you like, the season expectations will be easier to accomplish, but you will have to play the game for 20 seasons and pay attention to keep you team competitive, it will take at least 100+ hours.