I have watched quite a bit of baseball, and have always wondered why almost every player immediately looks into the field after striking out.
- making sure the pitcher isn't staring them down?
- trying to see their replay on the video board?
I have watched quite a bit of baseball, too. There are some theories that can't be supported by any survey or reference that I can find.
They want to avoid eye contact with their manager, hitting coach or other players because they don't want to feel more embarrassed than they're already feeling.
They want to stare at a pitcher to deliver a message through eye contact, "I will hit it next time". However, pitchers usually turn their back after striking a hitter out to avoid any unnecessary eye contact because it doesn't help him to focus on the next pitch and in the worst case scenario, it could cause some misunderstanding between them.
They try to remember how the ball moved from a little farther place as if they were in a deck. Players try to see how the ball moves at a deck and it helps them to hit it better.
Note: I don't think it is related with their replay on the video board because I have seen them many times where they don't replay anything.
I've heard the player was checking the speed of the pitch which is usually displayed on the scoreboard after every pitch.
I have looked at three sites for the answer to this question, but none of them have the correct answer. First of all, it is a totally idiotic gesture, and most batters do it all the time. One of the reasons would be to see if the pitcher is laughing at them or doing a dance in celebration. But the main reason is to look at them viciously, while thinking in their mind that they will get them next time. Watch the best baseball movie of all, Bull Durham, and see what Kevin Costner is saying as he stares at the pitcher after he struck out.