What is going on with the NHL’s play-by-play data?
It’s something I’ve grown increasingly curious about over the past week or so, and a game on Wednesday night between the Toronto Maple Leafs and Montreal Canadiens offered a corroborating data point.
An astute observer noticed that the play-by-play data — the foundation for all historical counting measures and advanced measurements alike – was not matching the run of play. This data is collected for each game by individuals (or trackers) in home arenas as part of the NHL’s Real Time Scoring System.
In this particular case, Leafs centre Auston Matthews won a defensive zone draw, starting the transition up ice. Toronto defenceman Morgan Rielly attempted a shot in the offensive zone, and a full minute later after the faceoff was won, Canadiens goalie Carey Price froze the puck. But Rielly was never credited with a shot of any kind. Also of note: Montreal forward Nick Suzuki’s hit on Leafs defenceman T.J. Brodie was not recorded, nor was Suzuki’s earlier turnover.
Humans, not robots, are tracking the ultra-fast action in real-time. There is no expectation of perfection – in fact, the birth of hockey analytics was married to the reality of making adjustments to the data sets to improve quality. One obvious example? Combating home recording bias.
But there’s something unique about this season that makes me wonder if the issue has manifested in a bigger way. It wouldn’t be the first time that an issue was identified in this area. Just last season shot location data suddenly (and quietly) changed. When the broader stats community identified the issue, the NHL rallied to fix the problem and return shot location data to baseline.
Let’s take a look at the NHL this season compared to the beginning of the NHL’s Real Time Scoring System data, this time with a focus on offensive shot volume. (I’ve also added giveaway and taking data, notoriously less accurate than some of the other data we rely on, but I think it illustrates an important point).
I broke the data sets out by game state because I think there are peculiarities in the tracking when it comes to even strength play, though I’m not smart enough to figure out why.
If you look at the data sets, you see strong collinearity with increasing offensive production over the years – teams are taking more shots, they’re taking those shots from more dangerous areas, and they’re scoring more frequently. (It’s a big reason why league save percentages are down, year after year).
This season, teams are still scoring in line with prior years at even strength, and quite a bit more on the power play. But take a look at shot generation at even strength, which is down five per cent year-over-year and at a 12-year low. Consequently, shooting percentage is at a 12-year high.
That alone means little – it’s certainly possible teams have suddenly become more selective about where they generate these shots at even strength, trading quantity in for heaps of quality. But there are reasons to question that data. Among other things: teams appear to be wholly abandoning that strategy when it comes to the power play, generating shots in line with prior years and scoring goals at a considerably higher rate.
Other measures that have to carry a high level of accuracy, like penalties for and against, remain right in line with historical averages. And perhaps most notably, secondary measures – like even-strength takeaways – are down at such a considerable rate (25 per cent year-over-year) that they raise more eyebrows.
It’s not clear what the root cause of this is, or why there seems to be differentiation between even-strength data (which has deviated from recent years in competing directions) and power-play data (which is in line with recent years). But there has either been a considerable shift in offensive strategy around the league, or the work product of the trackers has changed.
In the grand scheme of things, this doesn’t appear a significant issue – there is still heaps of data being captured, and our understanding of what’s going on at the player and team level through these trackers remains strong.
But it does appear that we are losing data in some capacity. To that end, I invite my readers to send over any theory they have.
Data via NHL.com, Hockey Reference, Evolving Hockey
CLEVELAND (AP) — Restricted free agent forward Isaac Okoro has agreed to re-sign with the Cleveland Cavaliers on a three-year contract, a person familiar with the negotiations told The Associated Press on Saturday.
Okoro’s new deal is worth $38 million, according to the person who spoke to the AP on condition of anonymity because the contract has not been signed or announced by the team.
ESPN.com first reported the agreement, citing Okoro’s representation.
The fifth overall pick in the 2020 NBA draft, Okoro is Cleveland’s best perimeter defender, often drawing the assignment of guarding the opponent’s top scorer. Okoro also has worked to improve his offensive game.
The 23-year-old averaged 9.4 points and 3.0 rebounds in 69 games — 42 starts — last season for the Cavs, who beat Orlando in the opening round of the playoffs before losing to eventual champion Boston.
Okoro shot a career-best 39% on 3-pointers, forcing teams to come out and guard him.
His agreement caps an extraordinarily busy summer for the Cavs that began with coach J.B. Bickerstaff being fired and replaced by Kenny Atkinson. All-Star guard Donovan Mitchell signed a three-year, $150 million extension in July, ending months of speculation that he wanted out of Cleveland.
Also, power forward Evan Mobley signed a five-year, $224 deal and center Jarrett Allen signed a three-year, $91 million extension.
GUADALAJARA, Mexico – Canada’s Marina Stakusic fell 6-4, 6-3 to Poland’s Magdalena Frech in the quarterfinals of the Guadalajara Open tennis tournament on Friday.
The 19-year-old from Mississauga, Ont., won 61 per cent of her first-serve points and broke on just one of her six opportunities.
Stakusic had upset top-seeded Jelena Ostapenko of Latvia 6-3, 5-7, 7-6 (0) on Thursday night to advance.
In the opening round, Stakusic defeated Slovakia’s Anna Karolína Schmiedlová 6-2, 6-4 on Tuesday.
The fifth-seeded Frech won 62 per cent of her first-serve points and converted on three of her nine break point opportunities.
This report by The Canadian Press was first published Sept. 13, 2024.
TORONTO – Alejandro Kirk’s long single with the bases loaded provided the Toronto Blue Jays with a walk-off 4-3 win in the 11th inning of their series opener against the St. Louis Cardinals on Friday.
With the Cardinals outfield in, Kirk drove a shot off the base of the left-field wall to give the Blue Jays (70-78) their fourth win in 11 outings and halt the Cardinals’ (74-73) two-game win streak before 30,380 at Rogers Centre.
Kirk enjoyed a two-hit, two-RBI outing.
Erik Swanson (2-2) pitched a perfect 11th inning for the win, while Cardinals reliever Ryan Fernandez (1-5) took the loss.
Blue Jays starter Kevin Gausman enjoyed a seven-inning, 104-pitch outing. He surrendered his two runs on nine hits and two walks and fanned only two Cardinals.
He gave way to reliever Genesis Cabrera, who gave up a one-out homer to Thomas Saggese, his first in 2024, that tied the game in the eighth.
The Cardinals started swiftly with four straight singles to open the game. But they exited the first inning with only two runs on an RBI single to centre from Nolan Arendao and a fielder’s choice from Saggese.
Gausman required 28 pitches to escape the first inning but settled down to allow his teammates to snatch the lead in the fourth.
He also deftly pitched out of threats from the visitors in the fifth, sixth and seventh thanks to some solid defence, including Will Wagner’s diving stop, which led to a double play to end the fifth inning.
George Springer led off with a walk and stole second base. He advanced to third on Nathan Lukes’s single and scored when Vladimir Guerrero Jr. knocked in his 95th run with a double off the left-field wall.
Lukes scored on a sacrifice fly to left field from Spencer Horwitz. Guerrero touched home on Kirk’s two-out single to right.
In the ninth, Guerrero made a critical diving catch on an Arenado grounder to throw out the Cardinals’ infielder, with reliever Tommy Nance covering first. The defensive gem ended the inning with a runner on second base.
St. Louis starter Erick Fedde faced the minimum night batters in the first three innings thanks to a pair of double plays. He lasted five innings, giving up three runs on six hits and a walk with three strikeouts.
ON DECK
Toronto ace Jose Berrios (15-9) will start the second of the three-game series on Saturday. He has a six-game win streak.
The Cardinals will counter with righty Kyle Gibson (8-6).
This report by The Canadian Press was first published Sept. 13, 2024.
