The AI does so primarily in two different ways, both of which are impossible to detect unless using outside software
destroy them, then your opponent can draw cards equal to the number of monsters destroyed on their field
That means that if youve previously exiled lands with The Omenkeel
1 Rivendell
Amonkhet and Ikoria The first nod in favor of possibly playing 15 or fewer lands is if youre playing Amonkhet or Ikoria draft
You have Elves with uncommon Green abilities, like creatures that draw cards (Elvish Visionary, Multani's Acolyte), Regeneration (Ezuri, Renegade Leader), Lure (Elvish Bard), restock your library (Elvish Soultiller), creature search (Fierce Empath), and such