Originally Posted by
paradaxarada
This is legacy, the decks usually play with a tons of cantrip and it's not unusual see sideboards even with 15 different cards on the format.
Different of other formats, here is more apropriated to dose your 15 slots in a pretty generic way, and have some good and different options for each match up, I don't see this 1-of thing as a problem.
But, I can discuss arguments about things like "Isnt't more apropriated to play -1 Etherswarn Canonnist; +1 Meddling mage (or vice versa), for those reasons: (and explanain why, like: it be more embracing or deal with some specific threats that the deck is having some trouble to deal)
Also, the deck already play with a lot of good tutorable options (thanks to Trinket Mage) to deal with specific strategies, play with other spells and creatures is just make use of some possibilities to fill in gaps and take more advantage of some cards (Cavern of Souls).
I do not think it's coincidence not to see so many decks with Enlightment Tutor on the sideboard doing well on big tournments, I believe this is a overcome way to build sideboards, which is still made by insistence or personal preference by some people (nothing personal, I used it a lot back in 2013/14 and really like the card).