On the surface, Alex Galchenyuk had a rebound 2017-18 season. He played himself off the third and fourth line, showed good chemistry with Jonathan Drouin, and recorded decent offensive output (19 goals and 32 assists) on an offensively challenged Montreal Canadiens squad.

However, Galchenyuk’s campaign was largely fueled by the American sniper’s power-play prowess, in a system that, with Shea Weber out of the lineup, reinvented itself to focus on the Milwaukee native’s one-timer. The reality is that Galchenyuk’s five-on-five production, and especially his goal-scoring, has been slipping over the last two seasons.

The reasons for this decline are not obviously clear. Within this two-year span, Galchenyuk has enjoyed consistent stretches of time at both left wing and centre, he has played for both Claude Julien and Michel Therrien, and he’s arguably enjoyed the most linemate stability he’s ever had in his career: Alexander Radulov in 2016-17 and Jonathan Drouin in 17-18 in particular. He’s been hampered somewhat by injury, but his effort level was sufficient to restore him to the top six.

Yet despite Galchenyuk’s travails, his offensive output slid unabated. One reason for this may be the Canadiens’ transition from an offensive-minded defence corps to a more stay-at-home unit.

Whether by choice or by default, the Canadiens have played the young American alongside more defensive-minded rearguards in the last two years, and over the last four years Galchenyuk has seen his main defensive partner transition from P.K. Subban to Andrei Markov to Jeff Petry to Jordie Benn.

This seems like a sensible move. Galchenyuk has never been a defensive stalwart, after all. However, the data indicates Galchenyuk does significantly better with a more offensive-minded approach.

Unsurprisingly, the Canadiens generated more offence when Galchenyuk was on the ice with the likes of Subban and Markov versus Benn and Alzner, but what should be alarming is the widening gap between offensive and defensive defencemen. In the first two years of the sample, the Canadiens did not have the players to run a logical pairing of two defensive defencemen. In 2017-18, they did not have the players to run a logical pairing of two offensive defencemen. The long-term injury to Shea Weber — the one player in the “defensive” category who can generate offence at elite levels — also contributed to the gap.

Further exacerbating the issue is the fact that playing Galchenyuk with supposedly defensively responsible players is doing nothing to actually keep pucks out of the Canadiens’ net. Aside from 2016-17, when the Markov-Weber pairing was absolutely dominant, Galchenyuk has done better at preventing goals against when playing with offensive-minded rearguards in every season. The shift from offensive to defensive blue-liners has turned Galchenyuk from a net goal-positive player into a net goal-negative one at five-on-five.

There is one notable exception to this trend, and it’s one that Canadiens fans may not want to hear: Alex Galchenyuk cannot play with Jeff Petry. The duo generates less offence than Galchenyuk with other offensive defencemen, and are more porous defensively than Galchenyuk with defensive defencemen. This trend has persisted through the entirety of Petry’s Canadiens career, through different coaches, schemes, defensive pairmates, forward linemates, and so on.

Setting aside Galchenyuk’s struggles with Petry, which are more difficult to explain, the forward’s problems when playing with defensive-minded blue-liners may be due to his playstyle. Regardless of whether he lines up at wing or centre, Galchenyuk has always thrived in the middle of the rink. As a winger, #27 seeks to cut in. As a C, he tries to charge or split the D. Galchenyuk’s style is to use lateral movement to sow confusion and create space, and as his goal location maps will attest, he doesn’t shoot off the rush very often.

It’s not surprising that Galchenyuk’s goal map would be more slot-centric than that of a more stereotypical shooting winger like Max Pacioretty. However, it is highly surprising that Galchenyuk’s production is more tethered to the slot/netfront than that of Brendan Gallagher!

When Galchenyuk cuts into the middle, it means that the D must activate in order to keep the play alive in the offensive zone in the event of a turnover, or to exploit gaps created by Galchenyuk. Passive defencemen who stay glued to the offensive blue line create a gap between the driving Galchenyuk and themselves, which the defending players can easily exploit.

For an example of this, take a look at this goal scored by Galchenyuk against the New York Islanders on March 2, 2018:

Off a save by Charlie Lindgren, Galchenyuk receives the pass and charges down the ice in transition. As he crosses the blue line, he and Andrew Shaw are surrounded by three of the four Islanders skaters on the ice.

Galchenyuk cuts to the middle, drawing two of the original defenders as well as the trailing Islander backchecker. Knowing there are three bodies around him and the fourth is next to Shaw by the net, Galchenyuk expertly drops the puck back into what he knows is open space, where David Schlemko is waiting.

If Schlemko stops at the blue line, the pass goes to the side boards. Schlemko would still likely be first onto the loose puck, but the momentum of the play sputters and the Islanders have a chance to recover. Instead, Schlemko’s jumping up into the play sees him receive the puck with half the rink to himself.

As Schlemko drives the slot and shoots, Galchenyuk too moves deeper into open space, shedding himself of the Islander forwards.

As Galchenyuk pounces on Schlemko’s rebound and slams it into the yawning cage behind Jaroslav Halak, there isn’t an Islander inside the hashmarks.

There is no question that Alex Galchenyuk is an extraordinarily talented offensive player. The best way to maximize those gifts is not to give him safety blankets, but to give Galchenyuk players who are able to play on an equal plane with him; those who have the hockey sense and intuition to take advantage of the chances that he creates. As the Soviets and Europeans realized half a century ago, hockey is a game of five-man units, not independent forward trios and defensive pairs.

It’s time the Canadiens ensured their defence acted in unison with their forwards.

(Statistics via Natural Stat Trick. Goal map visualizations via HockeyViz.)