Then MLB got a little greedy and starting emptying the parks between games so they could charge twice. That kind of killed the doubleheader and now they only have doubleheaders for makeup games, I believe.
But let's say we had scheduled doubleheaders every Saturday and Sunday for the 26 weeks of the regular season. That would account for 104 games right there. Then add holidays - Memorial Day, Independence Day and Labor Day and that's 110 games.
That leaves 52 games left to finish out the 162-game season. Monday and Friday single games, which gives the teams Tuesdays through Thursdays off (or to make up rain-delay games).
Even better, have the same teams play each other during a given Friday-Monday stretch. These are six-game series.
I think that would bring a lot more interest into the game as opposed to the mind-numbing monotony of the MLB season we see today.
Better expand the roster to add more pitchers, because you would use 6 starters in 4 days. Might want to add another catcher and a couple of relievers too. And you have to pay for all that with a lot less revenue from ticket sales.