@smmenen Thank you, I changed it to the "DCI" in my initial post. I sorta knew that and had a brain fart.
Question: do you think their principles for restriction extend all the way back to cards like Ancestral and Time Walk? Was there ever a time when they would have said "these cards are not automatically restricted we have to evaluate the format?" What were the competitive balance reasons that any of the moxen should be restricted? What degenerate things did they enable that could not be enjoyed by many many different deck? I have my own theories as to why they got restricted in the first place, but I'd also like to hear from the community.
I preemptively answered these questions in my post you replied to:
"I ... found that the DCI's bases for restriction have evolved over the decades of Type I and Vintage play, and is not entirely consistent or internally coherent. They have evolved just as the game has."
It wasn't until 1995 that the concept of "card advantage" came into parlance. It makes sense that the regulatory body who manages Constructed Magic would also evolve their rationale and bases.
As I demonstrate in my History of Vintage, many of the restrictions that occurred in 1994 were done without the benefit of tournament data. Rather a handful of cards were immediately restricted after Antiquities and Legends were released. For example, 3 cards were immediately restricted after the release of Antiquities: Ivory Tower, Feldon's Cane, and Candleabra - but curiously - Workshop wasn't restricted until more than a month after that - suggesting that it was evidence, not just a preemptive design act, that precipitated it.
Similarly, Library of Alexandria was restricted more than 5 months after Arabian Nights was released, and well after other Arabian cards like Rukh Egg had been restricted. Again, this suggests that data or tournament experience/results played a role. And again, Mind Twist was restricted immediate after Bo Bell's victory at US Nationals. And, yet again, Balance and Fork were restricted after decks appeared abusing those cards in tournaments in early 1995.
After Legends, the DCI moved away from the idea of pre-emptive restrictions. The only card preemptively restricted - or restricted nearly immediately - after the release of a set, from 1995 until the present - is Mind's Desire. The soonest card's get restricted in that period is at least 2-3 months after set releases, compared to the virtually coterminous restrictions that occurred with the release of Antiquities and Legends.
If you follow the pattern of restriction from 1995 through April 1999, it's very clear that the DCI only restricted cards in Type I that were proven problematic, and was generally narrowly tailored in doing so. The main exception to narrow tailoring, of course, was the mass wave of October, 1999, when the DCI restricted 18 cards. But that occurred only after two prior attempts to deal with the problem proved futile.
Then, if you look at the restriction regime from late 1999 until roughly 2006 or so, it's clear that part of the rationale that the DCI uses for restricting cards is "function," like "fast mana" or tutors. Yet, it's very clear that by 2008 through the present, that rationale is jettisoned. And thus, cards like Chrome Mox, Mox Diamond, Grim Monolith, Burning Wish and Gifts Ungiven are unrestricted despite being "fast mana" or "tutors."
In short, the DCI's rationale has evolved over time as the game has evolved, in both our collective understanding and the emergence of better and more refined data sources and data sets. The MTGO era gives the DCI more and better data than ever before. And it's clear from a number of recent DCI announcements, written mostly by Ian Duke, that they are using that data.
Beth Moursand wrote an Duelist article that explained the rationale of every restricted card in Type I from 1994 through 1996. And the DCI has offered public explanations since roughly 1999, so we aren't entirely in the dark on what their rationale is. Your post seems to suggest we are completely in the dark. We aren't. That doesn't mean that their explanations are entirely comprehensive, but this isn't entirely guesswork either.