A focus on winning also often distracts players from the things that are in their control: giving their best effort, keeping the right attitude no matter the circumstances, and playing aggressively. By shifting the focus to factors in your control, you will perform better because you now have something to strive for that is achievable no matter the circumstances. You are now focused on the process of how to win instead of the outcome not within your control.
To put this into action, change the way you define success. Base success in a game off performance metrics, attitude, effort and aggressiveness. It is not very helpful to base success off of the outcome: How many times have you performed well and lost or performed poorly and won? By concentrating on performance and breaking it down into attitude, effort and aggressiveness, it will be much easier to succeed and you will put yourself in a better position to help your team win more games. You can ask yourself these types of questions to evaluate your performance:
Attitude: Did I stay positive no matter the score? Did I argue calls with the ref or accept them and move forward? Was I excited to take on the challenges of the game like playing hard while tired and facing tough opponents in 1-on-1 situations?
Effort: Did I strive to execute plays as best I could? Did I execute legal checks at every opportunity? Did I play my individual role well, working as part of the team? Did I use my best skills at every opportunity? Can I honestly say I left it all on the field?
Aggressiveness: Did I work to cause turnovers at every opportunity? Did I hustle for every ground ball and 50/50 ball? Did I continually work to score/help my team score, even if we were up by a lot (the best defensive is a strong offense) or down by a lot (never gave up)?
When you define success based off of the things largely in your control and ask yourself questions like those above, you will begin to play with more confidence and feel less pressure, because success is now something that is in your control. Redefine success on the field by focusing on attitude, effort, and aggressiveness.