How do you define “winning”? That's a tough call, and can vary a lot from person to person. When it comes to practicing, I personally define winning as accomplishing my goals for that session. Set big goals, like a recital, concert, recording project, or even just learning a new piece. Once you have a big goal, set a series of smaller goals that you will lead you the big goal. Then, make sure that you are always setting little goals for your practice sessions that line up with that path. Be sure to make these goals realistic for the time you have to work, but still challenging enough to keep you engaged. Making the goals too ambitious could cause problems. If you are not able achieve the small goals, it is easy to become frustrated and which may cause you to give up. But, by continuing to reach these little achievable goals, you will eventually reach the big goal. As long as you are improving and moving forward, you are winning!
If you are thinking about a career, my goal is always to be moving forward. I am constantly setting new goals and new projects, but never in order to compete with anyone else. The idea of competition in music is very antithetical to the nature of what music is, so it is counterproductive to compare yourself to the “success” others around you. There is always room at the top for everyone who is willing to do the work. Some people may be further along their journey, but as long as you keep moving, you are winning.
In life, the idea of “winning” can get very complicated. That being said, I prefer to simplify it: are you happy? Make sure that all of the goals you set, and the work that you do to achieve those goals makes you happy. You will never be happy all of the time, no one ever is, but if you are making the effort to do what you love and what you are passionate about you will find the good outweighs the bad. I have been very fortunate in that I have a wonderful family, a nice place to live, food on the table, and I get to make music for a living – that's a pretty big win!