MTGNexus

I know, 42 lands, with Crop Rotation being able to step in as a 43 land and Azorius Chancery counting as ~2 lands in certain situations sounds ridiculous, but I don't run any other ramp and, since the deck is mostly made of reactive spells, missing a land drop often means going to cleanup. All things being considered you really should be mulling any hands that don't have at least 3 lands, and if you want to expect 3 lands in your opening hand, you ought to run 43, phelddagriff lists run a lot of lands, and mine probably runs more than most other lists, but it feels right when I play it so ¯\_(ツ)_/¯

It does look kind silly, but I think having one to tutor for, or sandbag in your hand is really good, it's a lot easire to hold back your board wipes when you have an emergency fog should things get out of hand. Having multiple, however, and they really drag you down, the other option is Teferi's Protection, but I've been unipressed by that card, the ability to use Moment's Peace twice, or mill over it with Life from the Loam and still get some use out of it makes it much better in my book, I realize Teferi's Protection saves you from Torment of Hailfire and co., but I have other options against those spells, I just don't think the extra versatility of Teferi's Protection beat the double use you can get out of Moment's Peace

This is the hill I will die on, DirkGently doesn't seem to impressed with this card, but I consider it to be an essential part of the tutor package and a strong source of generic value. It just has so many options.

Early game, don't be afraid to turn this card into a land by grabbing Azorius Chancery, picking up some other land, then replaying that land, seriously, if you desperately need Crop Rotation back later, you have Mystic Sanctuary.

Late Game, you can hold onto this card until you need one of your answers (Arcane Lighthouse or Scavenger Grounds, but if you don't think you will need it, just grab Bonders' Enclave and be done with it.

the card works great with Life from the Loam, not only allowing you to get your lands back, but you can also sacrifice your cycle lands (Desert of the Indomitable and co.) or Boseiju, Who Endures/Otawara, Soaring City and then use them as cyclers/spells after you loam them back up. Seriously, this is a big one, it's a lot easier to play these lands as lands when you know you can get them back later (another reason I like running one of the Karoo lands).

those are all great reasons to run this card but the biggest one is simply being able to tutor chain your way to Scavenger Grounds, Kor Haven, or sometimes, Arcane Lighthouse. these lands don't do anything if there stuck in your deck and they are often the best, or even the only way to handle a situation at the table.