First off, you might be better off posting this question in the 'Formations and Tactics' forum, that is where most of the in-depth strategy discussion happens.

Second, I think you will have to give a lot more information if you want to get useful advice. The fact you play 4-5-1V doesn't really say a lot other than that if you always play the same formation beyond a certain level, then other managers will read and react to you and play an effective counter. Specifically it would be helpful to know:

- What level you are in?
- What kind of formations are you losing to?
- Are you getting comprehensively beaten, losing possession, chances etc or just last minute 'lucky' goals etc?
- What team orders and 'arrows' are you playing with your 4-5-1V?
- Do you watch games for the possession bonus? Do your opponents? Do their friends?
- Have you tried any other formations (either for a whole game or as a tactical change)? If so what were the results?