Word to use when you don't understand a sport or video-game language [duplicate]

Solution 1:

The word typically used for this is jargon:

Special words or expressions that are used by a particular profession or group and are difficult for others to understand.
_{Oxford Dictionaries}

For example:

• Video Game Vocabulary, Jargon, and Slang - Lee Laughead's
• The comprehensive guide to sports jargon | FOX Sports

Solution 2:

One word for this is lingo

Defined by Merriam Webster as:

b : the special vocabulary of a particular field of interest The book has a lot of computer lingo.

Guy 3: They are using so much lingo that can't understand a word they're saying.

And just for grins, since your question used Baseball as an example, here's a site on Baseball Slang and Lingo