Make the team well balanced, not the person

You're the coach of a baseball team. Timmy is a strong pitcher, but weak batter. To improve Timmy's value to the team, which do you spend more time improving: his pitching or batting?

I hope you chose pitching. Because to win more games, you develop your players' strengths, not weaknesses. If you spend time addressing players' weaknesses, you may have well-balanced players, but not a well-balanced team. Bottom line: Spend time developing players' strengths, not weaknesses, because well-balanced teams wins more games than well-balanced players.