Paper

Methodology

How I count everything on Paper Puck, how the expected-goals model works, and how well it holds up. It's all built from the NHL's own public play-by-play and shift data. Pick a topic below, or scroll down for the glossary.

  • The data

    Where my numbers come from, and how I count shot attempts, strengths, positions, age and shooting luck.

    Where does it all come from?The NHL's own play-by-play and shift charts, every regular-season game since 2019-20.

  • Expected goals (xG)

    How my expected-goals model works, how well it held up on a season it never saw, and whose ideas it's built from.

    How often does a shot like that go in?Tested on a season it never saw, its goal total came out about 5% high.

  • Score & venue adjustment

    Teams that trail or play at home outshoot their opponents. How I adjust for that, so neither flatters a team.

    Is a team flattered by trailing or playing at home?Tied at 5v5, home teams take 51% of the attempts (2026-27).

  • Deserved to win and expected points

    Every game replayed from its shots: who deserved to win, and what a team's shots were worth in the standings.

    Who deserved to win?Each game replayed from its shots.

  • Win probability before a game

    Each team's chance before a game, from my own xG, and how well that held up when I replayed past seasons.

    Who's favoured tonight?Hockey's close to a coin flip: favourites won about 60% of past games.

  • Goalies: danger and rebounds

    How I split the shots a goalie faces by danger, type and distance, and how I count the rebounds he gives up.

    Which shots beat him?His saves by danger, shot type and distance.

  • With or without you (WOWY)

    How a skater does with each teammate and apart from him, and why that can't tell you who's carrying whom.

    Is he better with him, or without?Each teammate he's played 50 minutes or more with at 5v5, together and apart.

Glossary

Every abbreviation on Paper Puck. On-ice figures count what both teams did while the player was on the ice; a team's are its own. Counts are totals, or per 60 minutes under the Display switch.

Time and games

GP · Games played
Games with ice time at the chosen strength; for a goalie, games with time in net. A game he dressed for and did not play is not counted.
TOI · Time on ice
Minutes on the ice at the chosen strength (for a goalie, minutes in net), read off the NHL's shift charts. Min TOI is the floor a row needs to be listed.
TOI/GP · Ice time a game
Minutes a game he played: in all situations (TOI/GP), at even strength (EV/GP), on the power play (PP/GP) or short-handed (SH/GP), with both goalies in, over the games he played.
TOI% · Share of his club's ice time
His minutes over his club's minutes at the strength in the games he played: TOI% in all situations, PP TOI% of its power-play time, SH TOI% of its short-handed time. Five skaters share the ice, so a regular reads about a third at even strength.
Per 60 · Per 60 minutes
A count divided by the ice time it was counted over, times 60: a rate over a full game's worth of minutes, so a player with more ice time does not look better for it. Shares and percentages are the same either way.
Games back · Last N games
Each skater's or team's last N games, counted back across the season boundary, in place of a season range. A game counts toward N when he played it, at any strength.

Strength and views

All · All situations
Every event and every second of a game, empty-net play included: the one strength that counts it.
EV · Even strength
5v5, 4v4 and 3v3 with both goalies in. Empty-net play is counted under All situations only.
5v5 · Five on five
Five skaters a side with both goalies in: most of a game, and the usual strength for comparing players.
PP · Power play
5v4, 5v3 and 4v3 with both goalies in, from the side with the extra skater. For a goalie, his team's power play.
SH · Short-handed
4v5, 3v5 and 3v4 with both goalies in, from the side a skater short. For a goalie, his team short.
On-ice · On-ice stats
Everything either team did while he was on the ice: he is on for an event when one of his shifts starts before it and ends at or after it. A team's figure is its own count of its events.
Individual · Individual stats
What he did himself: his goals, assists and shot attempts, at his team's strength when he shot or assisted. An empty-net goal counts under All situations only.
Report
Which set of columns a skater table shows, over the same rows: On-ice, Boxcar (his own counting stats), Luck (this season against his record and the league) or Usage (ice time by strength). Columns turns on the ones a report hides.
Boxcar · Boxcar report
His own counting stats: goals, assists, points, shots, expected goals, and the box score's hits, blocked shots and penalty minutes. Hits, blocks and PIM are whole games, so they show under All situations only.
Luck · Luck report
Is it real? His shooting %, on-ice shooting % and PDO beside his own record in the seasons before (since 2019-20) and the league's for his position (forwards and defence kept apart), with the differences and a z-score for his shooting.
Usage · Usage report
How he is deployed: ice time a game in all situations, at even strength, on the power play and short-handed (both goalies in), and his share of his club's time at each in the games he played.
Score & venue · Score and venue adjustment
Each shot attempt weighted by how the league shoots in that score and rink, so the average team reads 50% in every score state: a team that trails or plays at home outshoots its opponent. I fit the weights on the NHL's play-by-play.

Shot attempts, shots and goals

CF · Corsi for
Shot attempts by his team while he is on the ice: goals, shots on goal, misses and blocked shots.
CA · Corsi against
Shot attempts against his team while he is on the ice, blocked ones included.
FF · Fenwick for
Unblocked shot attempts for: Corsi without the blocked shots (goals, shots on goal and misses).
FA · Fenwick against
Unblocked shot attempts against. For a goalie, the unblocked attempts against him while he was in net.
SF · Shots for
Shots on goal for, goals included.
SA · Shots against
Shots on goal against, goals included. For a goalie, the shots on goal he faced.
SOG · Shots on goal
Attempts that reach the net: saves plus goals. Misses and blocked shots are not on goal.
GF · Goals for
Goals by his team while he is on the ice.
GA · Goals against
Goals against his team while he is on the ice. For a goalie, the goals scored on him; an empty-net goal is nobody's.
xG · Expected goals
How often an unblocked shot like that goes in, from where and how it was taken, by my own model fit on the NHL's play-by-play. Added up over shots, it's the goals the chances were worth. A blocked attempt has no location, so no xG.
xGF · Expected goals for
The summed xG of every unblocked attempt by his team while he is on the ice.
xGA · Expected goals against
The summed xG of every unblocked attempt against his team while he is on the ice. For a goalie, of every unblocked attempt against him.

Shares and differentials

CF% · Corsi for %
CF ÷ (CF + CA): his team's share of the shot attempts while he is on the ice. Above 50%, his team is out-shooting the other side while he's out there.
FF% · Fenwick for %
FF ÷ (FF + FA): his team's share of the unblocked shot attempts while he is on the ice.
SF% · Shots for %
SF ÷ (SF + SA): his team's share of the shots on goal while he is on the ice.
GF% · Goals for %
GF ÷ (GF + GA): his team's share of the goals while he is on the ice.
xGF% · Expected goals for %
xGF ÷ (xGF + xGA): his team's share of the chances while he is on the ice, each unblocked attempt weighed by its xG.
Rel · Relative to team
His on-ice share minus his team's share while he was off the ice, in the games he played, in percentage points (CF% Rel, FF% Rel, SF% Rel, GF% Rel, xGF% Rel). Above 0, his team did better with him on.
WOWY · With or without you
A skater's on-ice shares split three ways for each teammate: with the teammate (both on), him without the teammate, and the teammate without him. Usage and opponents are not taken out.
C± · Corsi differential
CF − CA: shot attempts for minus against while he is on the ice.
F± · Fenwick differential
FF − FA: unblocked attempts for minus against.
S± · Shot differential
SF − SA: shots on goal for minus against.
G± · Goal differential
GF − GA: goals for minus against while he is on the ice.
xG± · Expected goal differential
xGF − xGA: expected goals for minus against.

Shooting, saves and luck

Sh% · On-ice shooting %
GF ÷ SF: his team's shooting percentage while he is on the ice.
Sv% · Save %
1 − GA ÷ SA, on shots on goal. For a skater, his team's save percentage while he is on the ice; for a goalie, his own (the NHL's figure).
PDO · Shooting % plus save %
On-ice Sh% + Sv%. It tends to drift back toward 100. A number far from it is usually luck, though great shooters and goalies can stay above it.
before · His record before
The same rate over his seasons before this row's (from 2019-20, the first Paper Puck holds), at the same strength, from summed counts. Blank in his first season here or where an earlier season is not yet counted.
lg · League average for his position
The same rate over every forward (or every defenceman, as he is) in the row's seasons, at the same strength, from summed counts. Forwards and defence are kept apart.
Δ · Change from his record
This row's rate minus his record before, in percentage points (PDO in points of 100).
Sh% z · Shooting luck, as a z-score
How surprising his goal total is, given how he usually shoots: his goals minus what his shots on goal would bring at his expected rate (his record before, mixed with 100 shots at the league rate for his position), over the spread chance alone gives. Past +2 or −2 is coloured. For one player that happens by luck about 1 time in 20, so in a big table a few light up from luck alone. Greyed and uncoloured under 25 shots on goal, where the reading doesn't hold.

Individual

G · Goals
Goals he scored.
A1 · Primary assists
The last pass before a goal: the first assist credited on it.
A2 · Secondary assists
The second assist credited on a goal.
P · Points
G + A1 + A2: goals plus primary and secondary assists.
iCF · Individual Corsi
His own shot attempts, blocked ones included.
iFF · Individual Fenwick
His own unblocked shot attempts.
iSF · Individual shots
His own shots on goal, goals included.
ixG · Individual expected goals
The summed xG of his own unblocked attempts: the goals his chances were worth.
Sh% · Shooting %
G ÷ iSF: his goals over his own shots on goal.
G−ixG · Finishing
Goals minus individual expected goals. Above zero, he scored more than his chances were worth; it swings a lot from season to season.
A · Assists
A1 + A2: primary and secondary assists.
Hits
Hits he gave, counted from the NHL's play-by-play at the strength shown (at All situations, the same as the NHL's boxscore).
HitT · Hits taken
Hits he took, counted from the NHL's play-by-play at the strength shown.
Blk · Blocked shots
Opponents' shot attempts he blocked, counted from the NHL's play-by-play at the strength shown (a teammate's shot he got in the way of is not one).
GvA · Giveaways
Times he gave the puck away, as the NHL's scorers record them in the play-by-play. Scorers differ by rink, so compare with care.
TkA · Takeaways
Times he took the puck from an opponent, as the NHL's scorers record them in the play-by-play. Scorers differ by rink, so compare with care.
PenD · Penalties drawn
Penalties the NHL's play-by-play says he drew. Misconducts are left out: they put no one in the box for a power play.
PenT · Penalties taken
Penalties he took, from the NHL's play-by-play. Misconducts are left out: they put no one in the box for a power play.
Pen± · Penalty differential
Penalties drawn minus penalties taken. Above zero, his team got more power plays from him than it gave away.
PIM · Penalty minutes
Penalty minutes he was assessed, from the NHL's boxscore: whole games, so under All situations only.
FOW · Faceoffs won
Faceoffs he won, from the NHL's play-by-play.
FOL · Faceoffs lost
Faceoffs he lost, from the NHL's play-by-play.
FO% · Faceoff win percentage
FOW / (FOW + FOL). Blank when he took no faceoffs; a handful is noise, so read it beside FOW and FOL.
OZS · Offensive zone starts
Shifts he began on a faceoff in his offensive zone (from the NHL's play-by-play and shift charts).
NZS · Neutral zone starts
Shifts he began on a neutral-zone faceoff, period openings included.
DZS · Defensive zone starts
Shifts he began on a faceoff in his defensive zone.
OZS% · Offensive zone start share
OZS / (OZS + DZS): how much of his deployment off a faceoff was in the attacking end. Neutral-zone starts and shifts begun on the fly are left out.
Post · Posts and crossbars
His shot attempts that hit a post or the crossbar and stayed out.

Goalies

FSv% · Fenwick save %
1 − GA ÷ FA: save percentage on unblocked attempts (shots on goal and misses).
xSv% · Expected save %
1 − xGA ÷ FA, on unblocked attempts: what an average goalie stops of the same attempts.
dSv% · Save % above expected
FSv% − xSv%, in percentage points. Above 0, he stopped more than the attempts were expected to allow.
GSAx · Goals saved above expected
xGA − GA: the goals the attempts against him were worth, minus the goals he let in.
GSAx/60 · Goals saved above expected per 60
GSAx per 60 minutes in net.
Danger · Shot danger
Unblocked attempts by their expected goals: low under 0.05, medium 0.05 to 0.15, high 0.15 and up. The bands add up to his totals.
Lg Sv% · League save %
Every goalie's Sv% on the same group of attempts in the season, at the same strength.
Reb/100 · Rebounds allowed per 100 saves
Saves followed within 3 seconds, in the same period and with no play in between, by another attempt by the same team, per 100 saves.

Positions and record

Pos · Position
C, LW or RW from his latest game's boxscore in the range, F with no detail, D for defence. The NHL does not publish which side a defenceman plays, so defence is D; the Shoots filter is his handedness, not a side.
Shoots · Shoots / Catches
Handedness from the NHL's player profile: the hand a skater shoots with, or a goalie catches with. Blank when the NHL lists none.
Age
His age in whole years on February 1 of the season (2025-26: February 1, 2026), from the NHL's player profile; over several seasons, in the latest one. Blank without a birth date.
W-L-OTL · Record
Wins, regulation losses, and losses in overtime or a shootout.

Standings

GP · Games played (standings)
Regular-season games the club has played.
W · Wins
Games won, in regulation, overtime or a shootout. Worth 2 points.
L · Regulation losses
Games lost in regulation. Worth no points.
OTL · Overtime and shootout losses
Games lost in overtime or a shootout. Worth 1 point.
PTS · Points
2 for a win and 1 for an overtime or shootout loss: the NHL's standings points.
P% · Points percentage
PTS ÷ (2 × GP): the share of the points available that the club took.
ROW · Regulation and overtime wins
Wins in regulation or overtime: every win but a shootout's. A tiebreaker after points.
GF · Goals for (standings)
Goals in the final scores, as the NHL's standings count them: a shootout win adds one.
GA · Goals against (standings)
Goals against in the final scores; a shootout loss adds one.
GD · Goal differential (standings)
GF − GA in the final scores.
xPTS · Expected points
What the club's shots were worth in the standings. Each game is replayed from both sides' regulation shots, each a goal with its xG chance (empty nets left out): xPTS = 2 × P(win in regulation) + 1.5 × P(tied after regulation), summed over the games.
PTS−xPTS · Points above expected
PTS − xPTS: points taken beyond what the shots were worth. Finishing, goaltending, overtime and luck. The model expects fewer ties than the NHL has, so the average team sits a bit above 0.

The published work I learned these methods from is on the Credits page; What is borrowed, and what is new says which part came from which.