As of 2016, the Presiding Officer (i.e. Speaker) in the Scottish Parliament is Ken Macintosh.
The curious thing is that Macintosh is a former member of the Labour Party (Presiding Officers are expected to renounce party affiliation while in office), while the ruling party has been Scottish National Party during the same period.
If conventional wisdom serves, shouldn't the Presiding Officer be someone from the Scottish National Party? What is the political calculus that led to this result?