I tweet out a lot of charts. Here’s a primer on the most common ones.
Rolling penalties drawn and taken
Rolling shot totals
Rolling shot total histogram
Head to head ice time and Corsi
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A quick rundown of head-to-head TOI and Corsi in one or more games between two teams.
Lighter colors indicate more ice time. For single games, the scale runs from green to yellow. For multiple games (example), it runs from blue to white via green, yellow, and brown.
Corsi is listed from the perspective of the team on the vertical axis. Positive numbers are preceded by a plus sign; negative numbers are preceded by a minus sign and are circled. The numbers along the top and right edges are total TOI (in minutes) and total Corsi rating.
Note that in older charts, the total Corsi rating for players on the horizontal axis is from the perspective of the vertical-axis team. In newer ones, it’s from the perspective of the horizontal-axis team.
In this example (Alex Ovechkin’s best-ever game by Corsi), the Capitals’ top line played about 10-12 minutes against the Enstrom-Havelid pair and dominated them to the tune of ~ +23 Corsi. Ovechkin played 18.3 minutes and posted a +33 Corsi rating. Bobby Holik, on the other hand, was -18 vs Ovechkin, and in 14.8 minutes played overall, -23 total. (In newer charts, it would say -23, not +23.)
Forwards are listed first, followed by defenseman (as listed by the play-by-play—this means that a player who plays both forward and defense, like Dustin Byfuglien, could be listed with the blueliners even if he's playing up front, depending on what the official play-by-play lists him as). Forwards are grouped together as follows:
F1: the player with the most ice time
F2 and F3: the other players on F1's most frequent line
F4: the remaining to-be-listed player with the most ice time
F5 and F6: the other player(s) on F4's most frequent line (from remaining unlisted players only)
And so on, with a similar process for defensemen. This algorithm normally does a good job of identifying lines and pairs, but may get messy if a coach starts moving players around the lineup or if someone gets injured.
In the above example, Bruce Boudreau shuffled his defense pairs (likely a result of the team trailing by multiple goals and desperately needing a win), so the matchups aren’t as easy to discern as for the Caps forwards.
This chart isn’t necessarily to definitely say who won which matchup—a couple shots either way doesn’t mean much. Getting outshot by two shots per minute, on the other hand, is an indicator you were dominated.
Rolling Corsi
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A rundown of how Corsi changes over time for a given player. (I also sometimes do team-level charts—they’re similar.)
Corsi (or SAT) is 5-on-5 plus-minus, but for all types of shots (shots on goal, missed shots, and shots that were blocked by the other team) rather than just goals. It’s a proxy for possession and scoring chances.
In my individual-player charts, the solid black line is cumulative SAT%. The multi-colored line is SAT% with the player on the ice, as a moving average over the past 10, 20, or 40 games, for example. (Check the y-axis label for the exact number.) The broken line is team SAT% with that player off the ice (only counting games in which the player in question actually played). For reference, I added season ticks at the top of the chart.
In this example, it’s crystal-clear that Sergei Fedorov was a possession monster in the 07-08 and 08-09 seasons, even though the teams he played on were pretty good, possession-wise, too. (Remember that Columbus got some pretty awful goaltending that year—starter Fredrik Norrena posted a .904 in 55 GP, while backup Pascal Leclaire went for a .897 over 24 games.)
Usage charts
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This graph is a modified take on player usage charts popularized by Rob Vollman. The idea is less about contextualizing a player’s minutes (since quality of opposition, zone starts, etc, don’t have a significant effect on Corsi, aside from a handful of special cases) than getting an idea of how a coach trusts the players on the roster.
There are four variables plotted here:
- Forward quality of competition, based on TOI/60 (TOI% x 60 minutes)
You expect to see shutdown forwards and defensemen at the top of the chart. - Defenseman quality of competition, based on TOI/60
You expect to see the best offensive forwards at the right of the chart. - Zone start ratio (neutral-zone starts excluded)
Defensive-zone stoppers like Manny Malhotra will usually be in red, while offense-only players like Patrick Kane will be in blue. Pay special attention to the scale. - TOI/60
Bigger bubbles mean more TOI. Note that the scale is exaggerated to emphasize differences. In practice, most players don’t differ very much in TOI.
5v5 rate stat history charts
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This graph shows player 5v5 scoring by season, compared with rules of thumb for 1st- and 2nd-line scoring rates.*
The green bar shows goals and the blue, points — so here, for example, you can see T.J. Oshie scored about 0.6 goals per 60 and 2 points per 60 in both 2008-09 and 2010-11.
The horizontal lines are the aforementioned cutoffs: green for goals and blue for points. The dotted one is for the second line and the solid one for the first line.
*By definition, there are three players on a top line, and 30 teams, so 90 top-line forwards — the cutoff is the scoring rate of the 90th-ranked forward. Similarly, the second-line cutoffs come from the 180th-ranked forward.
Rolling penalties drawn and taken
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A graph showing how many penalties a team (or player) drew (or took) over a given time period (usually, rolling). For ease of analysis, penalties are put into five categories: obstruction, discipline, aggression, penalty shots, and other.
- Obstruction: hooking, holding, tripping, interference
Idea: what a player does when they’re beaten and need to impede progress of attacker - Discipline: high-sticking, too many men on the ice, diving, etc
Idea: what a player does when they’re not sufficiently attentive - Aggression: roughing, elbowing, boarding, charging, etc
Idea: intent to hurt, gone overboard - Penalty shot penalties
- Other: delay of game, fighting, and more
Rolling shot totals
Coming soon!
Rolling shot total histogram
Coming soon!
Hexagonal bin Corsi charts
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This type of chart a player’s Corsi% given his quality of teammates and competition, broadly speaking. Green hexagons indicate higher Corsi% and purple lower, with white 50%. (Bins that didn’t make the minimum-event cutoff are the color of the background.)
There are several variations on the charts. In this chart, we see Williams against specific forward quality of competition and defenseman quality of teammates (based on TOI/60—the average number of 5v5 minutes played by a player during each 60 played by the team), broken down into four graphs—each a different pair of linemates for Williams. You might also come across graphs separated by defense partner, forward line in support of a defenseman, or a single graph with everything combined. Names across the top axis of a given mini-chart are for reference—here, you can see Drew Doughty played north of 24 minutes per 60 for Los Angeles, so the hexbins at the far right of each mini-chart (high D QoT) involved Doughty.