Sport in Odd Years

The conjecture is that there's more public sporting events in odd numbered years than even numbered years.

Primarily this is because of the Olympics.

If you're holding an event every year (or every three years if that's a thing), there are as many during odd numbered years as even.

If you're holding one every two years, it would make sense to avoid even numbered years otherwise you'll clash with the Olympics, or at least preparation for one event will overlap with the other happening.

If you're holding one every four years, it make sense to avoid Olympic years for the same reason, and then there's a 2-to-1 chance that it will be in an odd numbered year.

So given all that, an arbitrary event is fractionally more likely to happen in an odd numbered year.

A possible complication would be an even that happens some time November to February, which is far enough away from the Olympics to not matter and to be straddling the year boundary so might even vary (eg happening approximately every 2 years but happens perhaps February 2010 then November 2011). However, Christmas means that's unlikely to ever happen, most events will have a fairly fixed date in the calendar.