Traditionally ballparks try to avoid facing to the West because the afternoon sun interferes with the batter being able to see the ball coming as most games are afternoon or evening games. With many pitchers pitching in the 90s and even 100+ mph, being able to see the ball is very important to the batter not only to be able to hit it but also for safety in the event of a wild pitch. This is also the reason there is an empty green space in straight away center so the batter can pick up the ball more easily.