How does this game work

How do you know which tactics to use, so many choices , how to get subs right if loseing game, you have 3 subs, it take time to get them on the field and short time to change tactics more than once, any tips welcome.

Another problem i find is players in 1 position can not move about the field, makes it harder to change and get things right , so many positions and not much time to get it right if its going wrong.

How does this game work is something that 90% of the players would like a definitive answer too. Trial and error is the only way to find out i'm afraid mate. Pick a formation YOU like and that YOU think is the best sign the strongest 11 for those positions and then tweek the tactics. Seeing what gives you more shots on target, goals scored/ conceded that sort of thing.

There is no right or wrong answer and if 10 people gave you thier formations and tactics chances are you'd get 10 different answers

By the way i agree the subs do take too long :D

Good luck on your journey

I also find if your on a winning run , how can you experiment with formations and tactics. I only have 1 account , but multi account users can mess with other accounts and get extra practice in.

Funny thing is I only change things if i get a bad result or spend hours thinking of what the hell i didnt do right, but i guess there are the odd upset results, but i dont have a clue how that happens lol

Either organise friendlies if you have any people you know playing the game or experiment with your tactics when your playing the 2 or 3 worst teams in your division. Sometimes there are shock results but early in the game which i'm guessing you are the bottom 3 teams should be rubbish.

I've been playing the same formation since the day i started and although i do change shape when i'm playing against teams stronger than me in the cups i generally stick to what i'm happy with.

1st as your new you need to pick a formation and stick to it for a season or two!, buy players to suit that formation and keep upgrading your stadium and accessories, dont over train your players so start with once per day! never before a match as not to tire your team before you play!,. You can move your players around!, you just drag a player over the position you want and press save, it is best not to play players out of possession in the long run as you lose your possession bonus during matches, you can get away with some like a DML IN A DL position thats not to bad but just dont try play a ST in a DC although you will probably come across teams with players playing in a stupid position but I advise against it!.
As for changing the game during live games you can do this by going to your formation settings and changing them! this can help or make it worse its a lottery really!, pluss depending what formation you start with you could put on another striker if playing 1 or 2, put on another midfielder if playing 3!, put on take off a defender!! can you see where im going!, no one here can tell you the correct way as every match is different due to many factor of the two teams!, only you can decide what you think is best.