Now the same thing for the Hart trophy, again with a 0.5% threshold:
Twenty years
Gordie Howe (1951-1970)
Twelve years
Wayne Gretzky (1980-1991)
Nine years
Bobby Orr (1967-1975)
Doug Harvey (1954-1962)
Eight years
Andy Bathgate (1956-1963)
Bobby Clarke (1971-1978)
Bobby Hull (1962-1969)
Seven years
Denis Potvin (1975-1981)
Glenn Hall (1958-1964)
Jaromir Jagr (1995-2001)
Phil Esposito (1968-1974)
Red Kelly (1950-1956)
Joe Thornton (2003-2010)
Six years
Guy Lafleur (1975-1980)
Milt Schmidt (1947-1952)
Stan Mikita (1963-1968)
Ted Kennedy (1950-1955)
Terry Sawchuk (1955-1960)
Five years
Bryan Trottier (1978-1982)
Darryl Sittler (1976-1980)
Larry Robinson (1977-1981)
Martin Brodeur (2003-2008)
Sidney Crosby (2013-2017) (current)
Tony Esposito (1970-1974)
Note that this list goes back to the 1946-47, which explains the absence of players like Maurice Richard, Howie Morenz, Eddie Shore, etc.
There are a few surprises here. Thornton and Sittler fared better than expected. Although I wouldn`t quite call them surprises, Harvey and Bathgate both look great according to this metric.
What more can be said about Gordie Howe? Everyone knows he was a top five scorer for twenty straight years, but how many know that he got at least a few (non-trivial) votes for the Hart for the same amount of time?
Crosby is the sole player with an active streak that qualifies for this list. Erik Karlsson has an active streak of three years, while Patrick Kane has two.
The biggest omission, obviously, is Mario Lemieux. Unfortunately, due to injuries, he never had a streak longer than four seasons.