Historically there has usually been a 2 year cycle for the chess world championship, but when Gary Kasparov and Nigel Short split from FIDE in 1993 there were two Chess World Champions and championships. It was a little confusing, and of course the timing was all over the place.
However in 2006 the Chess world finally reunified and FIDE has been struggling to organise it back into a 2 year cycle match system since then. Now we should see a Chess World Cup Tournament on odd years around October/November time and a Chess World Championship match on even years, again, around October/November time with the candidates match happening March/April time on the even years.
This seems like a good system, finally.... But knowing FIDE it will all go tits up at some point.... fingers crossed they hold it together.
Could someone explain to me why there was a world championship two years in a row and now we're skipping a year?