I used to play (as a kid) and watch baseball in the 90’s, it’s really not too complicated for the most part. There are definitely some rules that don’t get used very often that’ll take a season or two of regular watching to get the hang of, but they’re not critical.

Re the stats, here’s what I think. Baseball was the first sport to be taken over by nerds; the Nate Bronze’s of the world who collected statistics and used them, successfully at times, to predict things about the outcomes of events/games.

The nerds were introducing scientific management to the sport, promising the owners and managers that arcane statistics would help improve win rates, use funds more efficiently to choose which players to sign, etc, which would ultimately lead to more fans, higher engagement, more revenue. This is probably the plot of Moneyball, although I haven’t seen it (stats nerds are definitely the plot of moneyball, I just don’t know how they’re portrayed or what the outcome is).

My understanding is that the nerds were incredibly successful at infiltrating baseball management (at least in an advisory role), and I would not be surprised if their ethos spread itself throughout the spirit of the game—with broadcasters now being able to fill the silence talking about weird stats, rather than whatever kind of small talk they’d do in the 90s (viewing stats as a pillar of scientific management, we know what happens to capitalists who don’t keep up with advances in productive technology; they’re dustbinned).

So I don’t view the stats as critical; there was a time when they were just a thing people kept track of, but most people couldn’t tell you a single one aside from their favorite player’s batting average or RBIs. But depending on how deeply the stats have permeated into the culture of the fans, you may be a bit “left out” if you’re not vaguely familiar with some of the more popular things.

All of that said, I haven’t watched in many years so I don’t really know the current state of things.