Nah, I'll use this ball

Here is a head scratcher for you...

1. A pitcher always wants a new, clean ball to pitch with, but they always rub the ball down as soon as they get it.

Okay, I don't see a problem with point #1; the pitcher wants a new ball, but doesn't want all the shine and oils on it.

2. If a pitcher throws a ball in the dirt, it is immediately thrown out.  In fact, the ump doesn't even decide to keep or toss the ball out; it is automatically taken out of play (mainly to save time).

Okay, still no problem here.

3.  If a hitter hits a ground ball out, the ball gets thrown around the horn, and it goes back to the pitcher.  Many times, the pitcher will just use that ball.  Yes, sometimes they do request a new ball.

Now, this completely goes against #1 and #2.  The ball was hit by the bat; it rolled, skipped, etc through the infield grass and dirt.  Why doesn't the pitcher just automatically throw this ball out and demand a new one?  Is it superstition?  I mean, the ball did just get him an out.

Any thoughts are appreciated!