We see this every year. The baseball season is long. 162 games is a grind. Someone comes out of the gate every single year on pace to break the HR record or hit .400. Slumps inevitably happen. Pitchers get tape on the hitter and ajust how they pitch to him. Almost every player deals with multi injuries over the course of the season that lower their level of play even though they don't go on the DL. It takes a pure hitting veteran HOF type player like Brett or Gwynn to even come close to hitting .400 over 162 games