In addition to , , and ratings - there are a few other factors to consider when scouting players and building your team(s).
EN is the 9th and final rating on the player card. A player's endurance rating influences how long he can go before fatigue begins to impact his performance. During each game, as players play, they slowly lose endurance. Pitchers lose endurance much faster than batters. As a player’s endurance gets low, fatigue begins to set in. Generally, the more endurance, the longer a position player can play without a day off, or the more innings a pitcher can throw before feeling the effects of fatigue. Endurance is recovered whenever a player has a day off, either due to being taken out of the lineup or his team having a day off. Typically, their endurance level will be fully recovered in four to five days. A players' endurance is displayed in the format - Current EN / Maximum EN. When a player is fatigued, their current EN is lower than their maximum EN.
You can not see season fatigue directly. However, if a player, when fully rested, never regains all his Endurance, you can bet that he's suffering from season fatigue in some degree.
For more information on Season Fatigue, read about the Fatigue & Resting Players.
Note: As of the June 2022 update, Season Fatigue is no longer shown directly in the UI.
Players have a hidden Righty/Lefty rating that reflects how they may perform better or worse against right-handed and left-handed opponents. Both the batter's and pitcher's RL ratings are used. In general, it is easier to hit against opposite-handed pitchers, and managers often take advantage of these matchups (hence you have a starting lineup against right-handed and left-handed pitchers).
Note: As of the June 2022 update, the Righty/Lefty rating is a hidden rating that will not be displayed