Depth charts are a ratio of who starts. Here's an example depth chart C: John Doe, Jack Black (20%) C stands for the catcher position John Doe is your starter at Catcher, Jack Black is the backup, who plays 20% of your games. Depth charts and tired players go hand in hand. If a player is tired, you increase the percentage his backup plays. Most players will be fine if you have their backup playing 10-20 percent of the time. Hope that helps