Wayne Gretzky vs. Bobby Clarke, December 1981: A Micro-Analysis

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Left image by “Centpacrr“, Right image by “Hakandahlstrom” via Wikimedia Commons, both altered by author

On December 30th, 1981, Wayne Gretzky’s Edmonton Oilers and Bobby Clarke’s Philadelphia Flyers met in a Wednesday night tilt rich with symbolism. Clarke, 32, was a couple of years away from retirement; two of his three remaining teammates from the Cup years, Reggie Leach and Bill Barber (defenseman Jimmy Watson was the third), were themselves out of the league in two years (Leach due to talent drop-off, Barber due to injury). Ironically, there was little indication in 1981 that this was going to happen – all were around 30, all were near point-per-game scorers playing all minutes. Whatever the case, they were the last of the Broad Street Bullies, and were now mentoring a new generation of “Bullies” like Ken Linseman, Tim Kerr, and Brian Propp, who seemed at times more annoying than dangerous. Though in transition, Philadelphia was still a great possession team (4th in the league in 2pS%, an historical possession metric), but fought the percentages all year to squeak into the playoffs. Edmonton, on the other hand, was romping through the league at record pace, and by December 30th held a comfortable lead over 2nd place Minnesota in the old Campbell Conference. Gretzky, of course, was at the heart of this surge, and by game 39 he had 45 goals.

The 1980s Oilers were the next step in NHL offense, really a Canadian version of the 1970s Soviet style of hockey. They didn’t need to bully their way to victories – they let the other team take the penalties, and skated all over them. I should say, that’s what Edmonton would eventually do; on this night they lined Gretzky up with Dave Lumley and Dave Semenko, as they had done most of the year. More on that later.

As I said before, though, the Flyers were a great possession team, as they always had been when Clarke and Barber were in their prime (they averaged, averaged, 55% 2pS% in the years 1973-74 through 1981-82, placing them consistently among the top 5 in the NHL). They were fast and calculating with their puck movement; the grit was just extra work – and who knows, maybe it contributed to Clarke, Barber, and Leach’s early retirement. The Bully when met with the Oilers, though, learned that the box was the bigger enemy.

I wanted to track the Oilers’ 7-5 victory that night in part because it was deep in the heart of the Oilers heyday, but also because it was against a known good-possession team and there was little incentive for score effects. You see, if Gretzky could get to 50 goals that day, he’d have reached that milestone in 39 games, 11 fewer than the only other two players to get 50 in 50 games or less, Mike Bossy and Rocket Richard. By the time he scored 4 goals that night, Glen Sather showed no signs of keeping Gretzky or the Oilers from pressing towards that 5th goal. What’s more, Clarke & Co. were doing everything to stop him – worth mentioning were 2 goals midway through the 3rd that kept it a 1-goal game – and at one point, Don Cherry (doing the play-by-play) lamented that Bobby was essentially going to ruin Cherry’s chance to see the record broken. Yup.

How did I know score effects didn’t come into play? Well, for one, I’ve tracked this game before, and for two I didn’t find evidence of the Oilers letting off the gas when they held a sizable lead:

Further to Gabe’s Oilers post, I broke apart 5v5 when the score was close and 5v5 when a team (in this case, the Oilers) had a 2-goal or greater lead, and in this game didn’t find any sign of score effects. For frame of reference, Edmonton held a 2+ lead for roughly 2/3 of the game. Of course, I need to look at more games, and those of you with the DVD “Edmonton Oilers 10 Greatest Games” know this is the game when Gretzky was going for 50 goals in 39 games. But hey, as one of the play-by-play guys (some recently-fired gentleman named “Don Cherry”) insisted, the Oilers were focused on the win, not the record. Probably because they were good Ontario boys.

I tracked through the game twice, the first time recording every offensive zone possession for either team, as well as the amount of that time when either Gretzky or Clarke were possessing the puck. I kept notes in the margin when either player recorded a shot, assist, or play of interest. I soon found it was just as fun to record how often Dave Semenko blew scoring chances that Gretzky gave him (usually by missing the net; I counted 5). The second time through, I did a shift-by-shift tracking of Gretzky and Clarke (measured in seconds):

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Either Gretzky, Clarke, or both players were on the ice for over 38 of the 60 minutes of the game (or about 63.5%); Gretzky logged 33.5 minutes of ice time to Clarke’s 21.2…17.1 of those minutes, Clarke was lined up against Gretzky (50.6% of Gretzky’s time, 79.9% of Clarke’s). Gretzky played over half the game, which to the stats eye is a testament to his perseverence…to the naked eye, though, he loafed around a lot. He was gassed. And who wouldn’t be? Each box above constitutes a “shift;” Gretzky’s shifts average 1:40 to Clarke’s 1:11. 30 seconds is a lifetime at that level, especially at the tail end of a shift. For a point of comparison, the longest shifts in the NHL in 1997-98 were taken by Ray Bourque, who averaged…1:09.

Their time, expressed as a percentage of their team’s total time at even-strength, on the powerplay, and on the penalty kill:

A comparison of Bobby Clarke and Wayne Gretzky’s TOI in their meeting December 30th, 1981. I expressed it above as a percentage of team total TOI at different strengths. As you can see, Gretzky was leaned on very heavily.

Clarke’s deployment is really in-line with what we see for forwards these days; and while Gretzky’s even-strength deployment is really high for a forward for our era, the caveat is that Sather was leaning on him (and Gretzky was likely pushing himself as well) to try and get the record. On the other hand, his percentage of powerplay time in this game pales in comparison to Alex Ovechkin’s 92.4% this year.

So that generally sets our TOI context, and we have a concise set of results: by my calculations, Gretzky had 11 shots on-goal, Clarke had 3, and by the boxcar calculations Gretzky scored 5, assisted on 1, while Clarke had 1 assist. All but one of Gretzky’s goals were at even-strength, though one of the 4 ESG was an empty-netter. Clarke’s lone assist was at even-strength, while Gretzky’s was on the powerplay (a 4v3). When on the ice together (remember, just over half of Gretzky’s minutes and 80% of Clarke’s), Gretzky had 5 shots, 1 even-strength goal, and one empty-net goal – Clarke had his one assist while Gretzky was out there.

Possession was where it got interesting. Take a guess at how much ice time actually involves a possessed (either under stickhandle control or passing control) puck in the offensive zone? Would you guess 24%? Of 60 minutes of playing time in this game, the puck was possessed by one of the teams in an offensive zone for about 14.3 minutes. Of that 14.3 minutes, Philadelphia had the upper hand of the possession battle, with 52% of the offensive zone possession to Edmonton’s 48%. Expressed as I would in a Fenwick chart:

Using individual offensive-zone possessions (measured in seconds), ordered chronologically by possession #, I charted the possession battle between EDM and PHI in 1981 on the model of the Fenwick chart. It’s obviously much tighter this way, so it’s interesting to compare it to a rolling average chart of the same data. The possession numbers quite neatly fell into, roughly, 60 possessions in the 1st, 2nd, and 3rd periods. As it appears up there, PHI edged the possession battle, 52% to EDM’s 48%.

The possessions (measured in seconds), quite neatly fell into rough groups of 60, period-by-period. Which is to say, each period had right around 60 offensive-zone possessions. You can also see the Flyers’ strength in possession by showing what percentage of time, at each strength, they possessed the puck in the offensive zone:

Expressed as a percentage of team total time at these strengths, the percentage of the time the teams actually possessed the puck in the offensive zone. This clearly demonstrates PHI to be the better possession team, despite losing to EDM 5-7.

The Flyers, in this game, did an excellent job controlling the puck in the offensive zone on the powerplay; only problem is that the Bullies only had about 4 1/2 minutes of powerplay to the Oilers’ 16 minutes. Within that team possession, we get a clearer picture of just how important Gretzky was to Edmonton’s possession in that game:

A demonstration of Gretzky’s importance to the Oilers’ offense in 1981-82, expressed by comparing his % of team total possession to Bobby Clarke’s. It goes up a tick for the powerplay, but it was always important in this game (12/30/1981).

So, if you can get your head around that…Gretzky, in that game, had 20% of Edmonton’s possession. That means, for every five seconds of possession for the Oilers, one second likely had to do with him. Clarke, as you can see, was around 5.5%.

We can also break down shot generation and assists with possession to identify the amount of possession either player needed before recording a shot or assist (had I tracked them, you could do the same with passes):

Tired of this game yet? Have data, will graph, so deal…with possession figures and shot totals, assists, we can also break down the duration of possession either player needed before recording a shot or assist. Part of me wishes I tracked passes, but oh well.

Didn’t see that coming, did you? I’m on-record as predicting that, in the future, we’re going to be discussing two primary things: 1) team talent related to possession (situationally quantified like we do Fenwick Close right now), and 2) an adjustment for teams that exhibit talent for shot generation during their possessions. That said, it sure is interesting to see how playing time had an impact on the difference of results between Gretzky and Clarke here. It’s a friendly reminder that Edmonton only won 7-5 (with an empty netter), and Philadelphia won the possession battle. But being a Bully was no longer the way, and the Oilers scored the difference while Flyers were in the box.

Just by doing two run-throughs on this game in 1981, we’ve been able to look at a wealth of data at the micro-stats level. Whether these measures are indicative of anything beyond the game is subject to debate; I’d say, individually, the jury is definitely out, as Sather was trying to get Gretzky the record. But the possession battle could be closer to the mark; 180 data points (read: offensive zone possessions) provide a robust sample, over double that of Fenwick or Corsi results, which stabilize at about 20 games. So this could be 1/10 of a pretty representative signal. Also worth pointing out: Philadelphia’s 2pS% on the year was 52.9%, and they went 52.1% in the possession battle in this game. Aside from Gretzky’s gargantuan TOI (I suspect we’ll find he played more along the lines of 25-28 mins/game), everything passes the smell test. Even Dave Semenko was his normal self; at one point, with a two-point cushion in the 2nd period, at 5v5 in his own zone and nearly by himself, he decided to try to freeze the puck against the boards. Everyone didn’t really know what he was doing, and neither did he…after looking around a bit, he decided against trapping it then shot a completely off-target pass up and out of the zone.

In the near future, I’ll be looking similarly at more Oilers games from the 1980s, in addition to other 1980s and late 1970s games to establish points of comparison. Barring some incredible influx of funding and invitations to archives, we’re not going to get all these historical games tracked – but even by doing some of the things I’ve done above, we can learn a lot about the past eras and players of the game.

8 thoughts on “Wayne Gretzky vs. Bobby Clarke, December 1981: A Micro-Analysis

  1. Wow. This was my childhood era. Great to see it broken down in this manner (and in a way that even I could understand it). Outstanding work!

    • I actually have the “Edmonton Oilers 10 Greatest Games” DVD…otherwise, they’re hard to track down. There are some games on YouTube as well.

  2. My brother suggested I may like this site. He was totally right.

    This post in fact made my day. You can’t consider just how so much time I had spent
    for this information! Thank you!

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