Your math is incorrect. While you are right there is a 1 in 32768 chance of it happening in every instance, each instance is a series of games. Not 15 games in one day or 15 chances in one day. So if you take 32768 / 162, the odds are this will occur once every 202 years.
I think this is correct - I got 202.2716 etc. However, this presumes a 50-50 chance of each home team winning. If you bump that to a mindfacted 55% the odds would improve to about 1 in 184.
But of course for many years there were fewer than 30 teams, thus fewer than 15 games a night.
And then you have nights where some teams don't play - were those games counted in the "never before happened" streak? Or was that a claim that only was made of the nights that 15 games occurred, a small subset of the overall history of MLB and thus a lesser accomplishment? Rhetorical questions, not expecting you to have those ready.
However, it would be a nice project for a WNFF newbie.
