Which types are most 'by the book' in your opinion?

From my experience I would say LSE / ESTj is most by the book. LSI / ISTj or ESI / ISFj is often said to be the most but imho LSE / ESTj is the winner. LSI is 'by the book' in a way but the book is their own internal understanding of the situation not as much an external source as such. ESI can often be 'by the book' but again their introverted nature makes them dismiss some external information if it doesn't fit what they see as right.

Which types are least 'by the book' in your opinion?

Well it should be LSE's conflictor IEI. I haven't been able to verify this. I could easily see ILE or IEE or even LII being least 'by the book'-type. In any case the most 'by the book' and 'least by the book' types should be conflictors (says my ).

So I conclude that one of LSE, LSI, ESI is most by the book. One of IEI, IEE, ILE is least by the book. "Black horses" in this competition are LII and SEE. Currently my "winners" are LSE and IEI.