Baseball is a game of adjustments. In the middle of a game a player will adjust on the fly - shortening his swing with two strikes, looking to drive the ball with one out and a runner on third - things like that. In between games, a player might experiment with different strategies based on previous outcomes, research he has done, or feedback he has received. In the offseason the adjustments are more preparation-based. Exercising certain muscle groups, adjusting diets, or increasing flexibility might be on the players agenda.
The organization goes through these same adjustments as well.