The NHL made a number of rule changes for the 2019-20 season. The league announced them on June 20, eight days after the end of the Stanley Cup Final.

With the new season rapidly approaching — the Senators and Maple Leafs will play the first game that matters Oct. 2 in Toronto — Sporting News takes another look at those changes:

An in-depth look at @NHL rule changes in place for the 2019-20 season. pic.twitter.com/BQFtOGJ9eZ — NHL Public Relations (@PR_NHL) September 17, 2019

Expansion of coach's challenges

NHL coaches have been able since the 2015-16 season to initiate replay challenges on scoring plays that occur after missed offsides calls or goaltender interference; this year, teams will also be allowed to challenge goal calls that follow plays in the offensive zone that should have resulted in a stoppage before the goal occurred.

According to the league, the change allows "challenges of plays that may involve pucks that hit the spectator netting, pucks that are high-sticked to a teammate in the offensive zone, pucks that have gone out of play but are subsequently touched in the offensive zone and hand passes that precede without a play stoppage and ultimately conclude in the scoring of a goal."

These "missed game stoppages" include pucks played with a high stick or batted down by an attacking player from the neutral zone to either themselves or a teammate in the offensive zone. "Missed game stoppages" that occur when defending players in the neutral zone play a puck with a high stick or by batting it to themselves or a teammate in the defensive zone would not be reversed by a coach's challenge. Challenges on pucks that travel out of play before a goal was scored would be successful regardless of whether an attacking or defending player last touched it.

Two such occurrences made waves during last year's playoffs. The Blue Jackets scored on a play in which the puck hit the net without on-ice officials noticing, and the Sharks won Game 3 of the Western Conference finals in overtime thanks to a secondary assist from Timo Meier's right hand.

Teams will only be able to initiate a challenge for these plays if the puck does not leave the attacking zone between when the missed call occurs and the goal is scored. Additionally, plays that require "discretionary stoppages," as the league puts it, cannot be challenged.

In both of the above instances, those goals clearly should have been called back but could not because neither coaches nor referees could initiate a review. The expansion of the coach's challenge should help ensure that goals that clearly should not have been allowed don't count and give on-ice officials a security blanket when they do miss a call.

Penalties for unsuccessful coach's challenges

Coaches can now initiate challenges at any time in-game, rather than only if the team has a timeout remaining. In the past, teams would lose that timeout should their challenge prove unsuccessful — now, teams will earn a minor penalty for delay of game after an unsuccessful challenge. The team will receive double minors for each additional unsuccessful challenge.

This change will add high drama to every coach's challenge. Teams will want to be confident they can get a call reversed before asking for replay in a close game.

The league's Situation Room in Toronto will still be responsible for initiating video reviews in the last minute of regulation and overtime. The league office has final authority over coach's challenge review decisions, for which it gathers input from and consults with on-ice officials and a former official in Toronto.

Referees to review major/match penalty calls

On-ice officials are now required to conduct video reviews for all major penalties (excluding fighting) and match penalties. Referees will be able to do two things in these reviews: "confirm" the penalty or "reduce" the penalty to a two-minute minor. They will not be able to rescind a penalty once it has been called. In these cases, the on-ice officials will not consult with Toronto for their review.

This is also an issue that came up in last season's playoffs. San Jose's Joe Pavelski was injured during the third period of Game 7 of a first-round series between the Sharks and Golden Knights. Vegas' Cody Eakin was assessed a five-minute major and a game misconduct, which led to an improbable comeback and a San Jose overtime victory to send the Sharks to Round 2. The league later apologized to the Golden Knights for handing out a major penalty for the play.

Video reviews will not be used to add penalties to plays, only to confirm or reduce penalties.

Referees to review double-minor high-sticking penalties

Similarly, on-ice officials will now be able to conduct a video review to confirm an initial call of a double-minor high-sticking, and in particular whether the stick that caused an injury was the stick of the player being penalized. Sometimes, a high-sticking is more than it appears at first glance — in those cases, the referees may rescind the penalty altogether. These penalties cannot be reduced to a minor penalty.

These reviews will occur at the referee's discretion and will not require consultation with the league's Situation Room.

Helmet requirements

It seems the days of a player roaming for an entire shift after losing their helmet are over.

According to the new rule, when a player loses their helmet during play, the player must either immediately leave the ice or retrieve the helmet and put it back on their head. This rule is vaguely worded, though; the league writes that players who are making a play on the puck when they lose their helmet "shall be given a reasonable opportunity to complete the play" before leaving the ice or retrieving the helmet.

Players who do not comply with these new rules will be assessed a minor penalty. If a player intentionally removes an opponent's helmet during play, they will be assessed a minor penalty for roughing.

The league noted when it released new rules in June that this rule would require "further consultation with the NHL Players' Association on precise language."

Defensive team line changes

The defensive team will not be allowed to make line changes when a goalie freezes the puck in their glove on shots taken from behind the red line. The same rule will apply if a skater on the defending team unintentionally dislodges the net from its moorings. In these cases, the attacking team can choose on which side of the net the faceoff will take place.

This new rule achieves the same effects as the icing rule — it prevents players from attempting to slow the game down to give their team rest.

If the net is dislodged and it cannot be determined conclusively it was caused by the defender's actions, the faceoff defaults to the regular dot and the defending team will be allowed to make a line change.

The choice of faceoff circles may seem innocuous at first, but it could make for interesting in-game decisions. Expect to see right-handed centers opting to take faceoffs on the right side of the net and send the puck to left-handed shooters, and vice versa.

Faceoffs following an icing and beginning a power play

In both instances, the offensive team will be able to choose which side of the net the faceoff will take place.

If a team does not indicate which side of the net they would take the faceoff on, the faceoff location will default to its regular location as determined by the on-ice officials.

Goaltender displacing goal posts on breakaways

If a goalie deliberately dislodges the net when facing a breakaway, the attacking team will automatically receive a goal. In the past, this infraction resulted in a delay of game penalty.

Pucks out of play

When the attacking team is responsible for the puck going out of play in the attacking zone, the faceoff will still take place in the attacking zone.

Puck drop after goals and start of overtime

Linesmen will drop the puck at center ice after all goals and at the start of overtime this season.