If you focus on hitting and ignore the defensive part of your game you will never be a complete player. Be as diligent on defense as you are on defense. Defense wins more games than offense. Pitching sets the tone. Games are lost not won.
Mistakes lead to losses.
You can win a league with a few good pitchers. Well developed pitching staffs win the tournaments. Work on your game every day of the year. The guy who beat you out for the starting job did and the team that always beats you did. Who you are today is a result of who you were in the past.