Idk
Malkin
Ovechkin
Kane
Crosby
McDavid
Benn
Bäckström
Hall
Kopitar
Giroux
Kucherov
Seguin
Stamkos
Tavares
MacKinnon
Kuznetzov
Gaudreau
Think you could make a case that all of them indeed had a chance based on either previous performance or actual performance during last season(s). Obviously some quite unlikely ones and some very much likely ones but they would still all be capable.
it depends on how you define "capable." to me, someone capable of winning an art ross is a guy who has multiple top 3s. the idea being, even if he never wins an art ross, if he has multiple seasons as a #2 or 3 guy, then in a year where everything goes right for him, he can make it over the top.
so obviously mcdavid, crosby, malkin, ovechkin, all are capable art ross winners. ovechkin maybe not so much anymore. kane and benn, who each have a #1 and 2.
claude giroux has a 2nd and two 3rds. so yeah, he's a possible.
kuch, 3rd and 5th. he's just entering his prime though, so i can give you kuch.
tavares, one single 2nd place finish (1 point back), four years ago; but i'll give you tavares because he was so close to winning it
mackinnon, one 5th place finish,
11 points back, so he would have to get better to be in range (but he's young so i wouldn't write him off)
after that,
backstrom, two 4ths, closest finish is
11 points back of the art ross
hall, two 6ths, closest finish is
15 points back
kopitar, has never finished top 5
seguin, has one 4th, in which he was 20 points back of the art ross; closest he's been is
10 points back (finish 7th)
stamkos, two 2nd place finishes, the last one of which was five years ago, hasn't been in the top 10 since; don't think he's capable anymore
kuz, finished 9th once. nope
gaudreau, finished in a three way tie for 6th once and was
28 points back of the art ross. come on
since expansion, how many players have won the art ross without at least one other top three finish? three: lindros (four top 3s in points/game), henrik sedin (finished 4th in his other great year), daniel sedin (finished 2nd and 3rd in points/game). those are your only "out of nowhere" art ross winners, none of them being actual out of nowhere cases, due to lindros' injury-abbreviated art ross-capable seasons and the sedins being a pair of guys who won it back-to-back.
so like i said, a guy can certainly come out of nowhere to finish 4th or 5th one time in his career, but i have yet to see someone come out of nowhere and finish 1st without repeating it or coming damn close.