"Knightfall" Proper was a fringe GW Type-2 deck from Alara/Zendikar which had wincons of Baneslayer Angel or ramping into an Avenger of Zendikar off a Turn 2 Lotus Cobra.
Parallel to this, it was a fast Type-1.X deck in the days where most decks were the slower UB Faeries+JTMS builds, and could easily punch through them by boarding out Harrows for more Scryb Rangers. With the Scars rotation of extended, it lost the Rangers, but gained more stability and out-of-the-gate punch off Harrows. By the time RG Infect and Jund were taking most tournaments, Knightfall ramp cards dwindled out and replaced themselves with Naya builds, running Plated Geopedes and Pyroclasms to fend off the wider decks. While the switch to a more stable deck worked on paper, it couldn't compete with most of the top decks, losing the last staying power it had had.
Upon the introduction of the Modern format, Knightfall was once again reunited with Scryb Ranger, and now had a stronger one-drop than Noble Hierarch: Sakura-Tribe Scout. As another instant-speed landfaller, a more comfortable combo piece with Scryb Ranger, and a body that can turn right on a dime, it provided larger swings to the deck that had been all but lost to time by this point. With a Ghost Quarter always a possibility, and the potential for instant-speed Bojuka Bogs, Knightfall had a steady win rate against graveyard-based decks, such as Storm, and land-based decks, such as Punishing Fire or Tron. The deck still had a crippling weakness in Jund, which was only amped up with its new toys like Liliana of the Veil and, later, Deathrite Shaman.
During the fall of 2012, as more and more Jund decks were switching to four-colour to become Lingering Jund, Knightfall fell further and further behind, until the only option was to adapt, with most lists replacing the Sakura-Tribe Scouts with Deathrite Shamans, Primeval Titans with Lingering Souls, and cutting one land for a Pendelhaven to slow down the deck again and provide a stronger mid-game and more air support.
Following the banning of Deathrite Shaman, the Scouts found their way back into many lists, but the Primeval Titans never returned to the deck, having found their niche in Kangaroo lists. While some Knightfall decks returned to the faster Naya build and began running the Geopedes and a Kessig Wolf Run as their wincon, others remained Junk, giving up some of their early game blitz-wins to maintain a well-rounded deck.
With the advent of Battle For Zendikar, Retreat to Coralhelm and its possibilities began to creep into play, with many players from modern to legacy using the term "Knightfall" to describe the Tactical Retreat combo, creating predominately combo decks and eliminating the breadth and evasive creatures of Knightfall Classic.
