Ultimately the Bruins gained zero advantage from the offside but it was still offside, more obviously so than any other goal they have had called back this season . How that was not called back is a huge mystery.
The Canadian announcer said that both skaters (Kuraly & Mac) were onside before McAvoy played the puck, (and that's what I thought it should be too), but when I found the PDF file of
NHL rule 83.1 - Off-side I couldn't find anything to back that up
http://www.nhl.com/nhl/en/v3/ext/rules/2019-2020-NHL-rulebook.pdf com
I'm guessing it's legit
Rule 83 – Off-side
83.1
Off-side - Players of the attacking team must not precede the puck into the attacking zone.
The position of the player’s skates and not that of his stick shall be the determining factor in all instances in deciding an off-side. A player is off-side when both skates are completely over the leading edge of the blue line involved in the play.
A player is on-side when either of his skates are in contact with, or on his own side of the line, at the instant the puck completely crosses the leading edge of the blueline regardless of the position of his stick. However, a player actually controlling the puck who shall cross the line ahead of the puck shall not be considered “off-side,” provided he had possession and control of the puck prior to his skates crossing the blue line.
It should be noted that while the position of the player’s skates is what determines whether a player is “off-side,” nevertheless the question of an “off-side” never arises until the puck has completely crossed the leading edge of the blueline at which time the decision is to be made.
If a player legally carries, passes or plays the puck back into his own defending zone while a player of the opposing team is in such defending zone, the off-side shall be ignored and play permitted to continue.
