More crazy facts about champs.
There were 342 "real" decks. (Excluding the non-sense decks) And 342 x 4 = 1368, which is the maximum possible number of any single card being played in the field. (Excluding basic lands).There were 528 copies of Mental Misstep at champs, or 39% of the maximum possible number. That is the highest number of any card.
As staggering as that number might seem, it shouldn't at all be surprising. On mtgtop8, Misstep is the most common card in vintage decks top8ing for the last year, when you count copies in sideboards. It's in 61% of mainboards, at an average of 3.6 copies per mainboard. So that's an even higher rate of saturation among top 8 decks. 55% of the maximum number of Missteps that could appear in top 8 decks of the past year.
Yet in this data that just got compiled from champs, (thanks again Matt and Ryan) there is basically no association with actually winning games. (At least going by Swiss points.) And the main reason for that is probably (and I'm just hypothesizing here) that there are just so many Missteps floating around. As many Missteps are on the winning side of match ups as losing ones. They just saturate the format.
The clear exception here is Shops and Eldrazi style decks that just sidestep the issue by playing few or no cards at the 1CMC level. And those decks do enjoy a better than 50/50 win rate as we all know. Which might mean that Misstep as a card is both, the most commonly played card in Vintage, and loses more games than it wins. (Though pitch Dredge might balance out its win loss somewhat in regards to Shops decks, I really haven't done the work to check out those hypotheses yet, and that would take a long long time.)