Baseball rules?

1

So, since the majority of the users here seem to be from the US, I feel confident that someone can answer these questions : )

I like baseball. It’s an entertaining sport, and we don’t really have it where I was born. So, I go to a lot of games etc etc. However, there are 3 things that are kinda confusing.

  1. Tag Up. The way I understand it, if a fielder catches a fly ball, the runners have to re-touch the bases they were at … at the time of the pitch. But sometimes they dont, they just keep running to score and the point counts. Wth? :confused:

  2. Whats the difference between a split and a sinker (pitches) ? They look extremely similar.

  3. Whats the difference between a z-s and a cutter (pitches) ? They look friggin identical.

Thanks :smiley: