Beyond the Boxscore: A handy glossary to key hockey analytics stats and concepts
Photo credit:Steven Bisig-USA TODAY Sports
1 month ago
Welcome back one and all to Beyond the Boxscore: Season 3 – a place to find out which Flames players had statistically great nights combined with some insight into what was working or not by myself (Shane Stevenson – @Flash_33 on X (formerly known as Twitter)). We’ll have charts, video breakdowns, colour commentary, and plenty of in-depth analysis.
CF% – , SCF% – , HDCF% – , xGF% –
Above here the metrics posted are the entire teams 5v5 SVA summary as posted by NaturalStatTrick.com. SVA stands for “score and venue adjusted” to account for the disparities in shot locations recorded by the 32 different league venues.
- CF% is the Corsi For percentage – this is the total amount of shot attempts whether they hit the net, were blocked, or missed. If a shot was attempted it was calculated here.
- SCF% is Scoring Chance For % – these are chances that hit the net and counted as a scoring chance. The level of danger does not matter to SCF%, all possible attempts are calculated here.
- HDCF% is high danger chance for %. This only calculates dangerous chances. Some people call them from the home-run area in front of the net. No not all goals come off high danger chances, but being able to constantly be on the better side of this metric means you’re most likely winning the quality share too.
- xGF% is expected goals for %, a quality of opportunity statistic. There are multiple expected goals models out there, but to understand them you first need to realize that every individual scoring attempt comes with a quality rating. You can take a bunch of low-quality shots and surrender very few against and still finish below 50% if those few chances against weighed more in quality share than say 10 weaker opportunities.
It has been easier to understand how a game flows using all 4 of these stats as a baseline – I also make sure to watch every single game to breathe insight into why these numbers ended up the way that they did.
It’s a Team Game – Here I typically break down from a team perspective. Look at individual periods to see if they dominated any aspect of the game for a stretch – and vice versa. In the two years covering at FlamesNation I’ve seen plenty of good games (2021-22) and plenty of bad (2022-23) so hopefully this year ends up being positive. If anything was pivotal in the outcome of the game one can expect it talked about here.
Corsi King/Clown – These sections I look at the individual players to see who won the shot attempt battle. I incorrectly call it possession sometimes, but I high level of possession typically translates to the higher number of shot attempts. These are group measurements though so if the LW screws up and lets a bunch of shots off the RW on the ice also gets dinged for those chances against despite not being at fault. The stronger the group play the stronger the metric. The higher the % the more attempts the player was on the ice for in comparison to whatever the competition happened to be in his ice time.
Under Pressure –
This chart is from the Flames pre-season tilt against the Jets. The higher the wave towards the respective teams side means they have a high number of shot attempts at that time of the game. When you’re watching and see a net-front scramble where a team gets 5 or 6 attempts that gets captured here by the wave extending far from the centre line. The farther from the centre – the more pressure created in that short span. The names are of goal scorers and the ping means they hit the post/crossbar.
Taken By Chance – This one might be the easiest for everyone to understand, but the stat I find many commenters disagreeing with. Simply put: the higher the % the more scoring chances you got than the other guys. I understand some may think that beamer wrist shot off the half wall was dangerous, but the models do not see it as such, and I trust a proven model over any random’s opinion on the topic every day of the week. I don’t record the statistics myself I just summarize them based on what is available to the public. NaturalStatTrick.com is free to access, the charts from HockeyViz.com I provide because Micah’s model is one of my favourites.
xG Breakdown –
The team with the higher tower got the most out of their cumulative quality. The larger the square the more dangerous the chance the player took. Red = goal, Blue = Saved, Dark Grey = Missed the net, Light Grey = Blocked. Oh yeah purple = post. This is from HockeyViz.com which has a paywall to access – its xG numbers may vary from that of NaturalStatTrick’s. As far as I’m concerned the more information the better.
xGF% – Quality share deserves a bit more of a mathematical explanation to understand. Lets say Jarome Iginla has 4 shot attempts each worth 0.25 xG – some high quality stuff. In comparison we’ll say Ryan Smyth had 5 shot attempts all worth 0.15 each. To make it even more simple we’ll say that all these attempts – no matter Iginla’s or Smyth’s – all happened while both guys were on the ice. Iginla equates to 0.25 x 4 = 1.00 xGF. (when there is no % I call it a raw number while the metrics with % I call ratios). Smyth then at 0.15 x 5 = 0.75.
We would say Iginla’s ratio was 1.00 to 0.75. It is calculated as xGF divided by (xGF + xGA).
- 1/ 1.75 = 57.1%
Smyth on the other hand would have his look like 0.75 / 1.75 = 42.9%
So, despite Smyth taking 5 attempts to Iginla’s 4 it was the Flames legend with the significantly better quality share because he took more dangerous chances. The Flames last season were a team that wanted a high number of shot attempts but didn’t always try for quality. They would look to have great xG as a result of piling up those 0.07 and 0.11 chances despite giving up more dangerous looks on their own netminder. For this reason I believe xG% and HDCF% always need to be looked at together – to truly understand what is happening with a players game.
Game Flow –
This m ay be the most complicated chart to read of all the ones here. It’s a different way of summarizing the xG bricks but just laying them out in chronological order. The part where the black line makes significant jumps means that chance was more dangerous than the others (it had a higher xGF raw number). The line always jumps in the direction of the team that took the chance, naturally. The coloured bars show where there is a power play – the line stays static because i choose to analyze stuff at 5v5 SVA rather than including odd-man situations into things. The majority of play is 5v5 – it is really what matters most. The coloured circles on the line are the goals scored in the match.
Game Score –
I post a graphic from X shared from the website HockeyStatCards.com. Game Score is a weighted metric that takes all of the other “fancy” stats we talk about in here and combine them with the boxscore stats (goals, assists etc.). You may have a bad game in terms of chances and quality but if you score a hattrick off three low quality shots you can’t say the guy had a bad game outright. This is where those come into play.
Shot Heatmap –
Where did the shots and goals come from. The scales on the bottom show the difference in colours. You want your chances to come exactly where the Flames have those 3 goals – denoted by the G on their side of the rink.
In The Crease – I know two things about goaltenders – big saves and bad goals. I’m not going to come here and talk about how to fix positioning or puck tracking because I don’t know squat about it. What I do know though, is whether or not the defenceman and forwards did a good enough job to help their goaltender out. If there are weak goals on a goalie we will call them out, but if blown coverage leads to high danger goals the defenceman responsible shoulder more of the blame.
Today’s Specials – I have not done a pre-season spot on this yet because the units keep changing so much but this is a section strictly to talk about special teams. Power play rants from what Kirk Muller had the guys doing dominated this part of the column so much I would exclude it every other game to quit from being repetitive. Here’s hoping Marc Savard can bring a little more flare to a power play that should have more power with the personnel they have.
Player Spotlight – Every game a player is highlighted whether it be because of performance, news outside the rink, my own frustrations with their play, or because I hadn’t talked about them enough in the summary. Who is going to appear here? Well, if someone scores a hattrick there’s a good bet I’ll need somewhere to expand on their praise and I use this section to do it.
The Goals – If you do not follow Robert Munnich (@RingOfFireYYC on X) then I will share all the goals the Flames score here. This whole post is to help you understand what happened if you missed the game, I feel obligated to at least include the videos of the goals for your viewing pleasure. But seriously if you’re a Flames fan and you don’t follow Robert what are you doing?
Flashalytic’s 3 Stars –
1) Johnny Gaudreau’s old home
2) Usually one of the defenceman find their way here
3) The “oh yeah him too” spot
(Stats compiled from Naturalstattrick.com // Game Score from Hockeystatcards.com // xG and Under Pressure charts from HockeyViz.com // Game Flow and Shot Heatmap from NaturalStatTrick.com)
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