That's because back in the day you had a lot more complete games, maybe one reliever. These days, it's not uncommon to see 5 or 6 pitchers for each team in a game. That's probably the biggest factor in longer games, and I don't know how you control that. Plus, more runs are scored these days, meaning longer innings. Again, can't control the fact it takes longer to score 7 runs a game than 2. So shorter games would offer less scoring, which is what the youth, casual fans, etc. want. Chicks (and casual fans) love the HR. So you can have a 2-1 game that lasts 2 1/2 hours, but that won't be popular either. Personally, I think if the commentators did a better job of explaining strategy more casual fans wouldn't mind a pitcherd dual or a 3 1/2 hour game. Instead, broadcasters tend to dumb it down thinking fans don't want to (or can't) understand game strategy.