Switching formations

One of the aspects of the game that always gets a bit of disagreement is the issue of switching tactics.

What the rules say:

You are able to prepare your team for how your opponent will play. If you think your opponent will play 4-4-2 you will be able to choose to prepare your team for that by selecting that formation in a dropdown list on the tactics page. The tactical option is possible to save within the default tactics.

If your opponent uses that formation this will have a negative effect on your opponent’s ability to create chances. How much effect it will have depends on how accustomed your opponent is to playing with that formation. That is determined by the formations used by your opponent the last 3 matches (including friendlies). The more matches (out of the past 3 matches) the opponent has played with a certain formation, the better he will be at playing that formation.

In other words this means that if the opponent uses a formation that he has used before and you didn’t prepare for that formation then your opponent will get a boost in his ability to create chances.

If you choose to prepare your team for a formation that the opponent won't use, then your opponent will always get a small positive extra effect on their ability to create chances. If you choose not to prepare your team for any formation then your opponent won't get any extra positive effect other than the experience they have on their formation used in the match.

Pros and cons of varying formations

If you switch formation each time it's likely your opponent will guess the wrong formation and you will gain an advantage because of that. The downside in this respect is you will never get a 3/3 formation so you don't get the maximum advantage available.

You also have the advantage of adjusting your formation to

This strategy may have worked well in the past but one of the big problems nowadays is so few formations are effective. 5 man mids (352/451) are the dominant formations and while 4 man mid formations can work they aren't as strong as 5 man mid. Anything else is just plain rubbish so you have limited options of formations you can switch too.

Advantages to keeping the same formation

One of the big advantages of playing just one or 2 formations all the time is familiarity and experience. You get to know what works so much better than when you are constantly switching all the time.

Another advantage of a single formation is there is no advantage to the opponent guessing how you will play, and if for some reason they guess wrong (it happens) then you gain a significant advantage.

Overall

Personally I tend to stick to just 1 formation with each of my teams. Varying it opens up the risk of the opponent guessing a 1/3 formation and almost always gives them a 2/3 formation advantage and I would much rather remove this variable. I can build my squad around the formation and get familiar with what attacking styles work.