What changed? Center Nico Hischier has produced at a higher rate with four power-play points after the trade compared to five power-play points in 27 games with Hall. One way to explain his increased production would be power-play time on ice per game. Hischier has averaged 2:50 per game since Hall was traded, versus 2:38 before. Another main difference is Wayne Simmonds' role reduction. The right wing went from skating on the top unit with Hall, averaging 3:08 per game, to the second unit, averaging 1:54 per game. This demotion allowed Hischier, Nikita Gusev, Sami Vatanen and Jesper Bratt to form chemistry on the top unit.
Conversely, Arizona's power play has declined from 20.8 percent (10th in the NHL) to 18.6 percent (23rd). This could be nothing more than Arizona's top unit trying to acclimate and form chemistry with Hall. Since Hall was acquired, the Coyotes' top unit personnel has been primarily Hall, Christian Dvorak, Clayton Keller, Phil Kessel and Oliver Ekman-Larsson. Before Hall arrived, center Derek Stepan was used on the top unit, but he has seen his man-advantage time on ice per game reduced from 2:45 in the first 35 games to 0:38 in the past 14 games.
At even strength, New Jersey with Hall was 27th at minus-149 in 5-on-5 shot attempts differential and is 24th (minus-65) since Hall left. The difference is small enough to suggest that Hall's departure has not affected the Devils at 5-on-5. Arizona was 25th in 5-on-5 SAT differential (minus-122) in 35 games prior to the trade and is 25th (minus-68) since Hall was acquired. Again, this suggests that Hall has not impacted either team's shot attempt output at even strength, which is reinforced by his minus-21 SAT with the Devils and minus-7 SAT with the Coyotes.
One interesting beneficiary for the Devils in Hall's absence has been Gusev, who improved at 5-on-5 going from a minus-41 SAT with Hall to plus-35 and a Devils-high 14 points (three goals, 11 assists) since the trade. Forward Blake Coleman has also stepped up by scoring nine goals in his past 14 games, matching his goal-scoring output from the first 32 games.
Coyotes forward Conor Garland has received a boost occasionally skating with Hall on the top line. Prior to the trade, Garland was minus-6 in SAT differential through 35 games but is plus-12 with Hall. Garland's impact has also shown on the score sheet. He has nine points (four goals, five assists) in 13 games (an average of 0.69 points per game) after having 17 points (12 goals, five assists) in the 35 before the trade (0.49 points per game).
It's too early to say definitively what kind of impact the Hall trade has had on the Devils and Coyotes, but so far it looks like it's one of the rare scenarios where it benefits each team. Other players in New Jersey have made the most of increased opportunities. Arizona has the point-per-game player in Hall that they've been seeking for years. To forecast what's to come, the Coyotes could challenge for first in the Western Conference when Kuemper returns. The Devils are unlikely to make the Stanley Cup Playoffs but have a chance to develop role players who will be instrumental in future success.