There’s a seemingly endless amount of hockey statistics. Many are commonplace, such as shots and goals. Some are openly debated, e.g., plus-minus (+/-). Some are often overlooked, like icing and offside events, or independently researched but not implemented on a large scale, e.g., shot quality. The backbone of icetistics.com focuses on those stats that are often overlooked, not commonly implemented, or completely novel in nature. Follow the links below to learn more.
Allow us to introduce “SHOAG”, a new statistic (to our knowledge) that quantifies a team’s ability of putting the puck on net. SHOAG is the ratio of Shots On Goal (shots and goals) to Shots At Goal (shots, goals, missed shots, and blocked shots; Equation 1).
SHOAG provides insight into the shooting discipline and efficiency of an offensive. It can be applied to teams, players, or combinations of players (e.g., linemates). Teams with larger SHOAG values are better at putting the puck on net than those with lower SHOAG values. The SHOAG stat also provides insight into opposing defenses. As with many hockey stats, the context of the game, such as score differential, period, etc. should be considered when using and comparing SHOAG among teams. SHOAG can be quantified in non-weighted (Eq. 1) and weighted (Eq. 2) form.
The weighted version of SHOAG (wSHOAG) considers the goal probability of each shot-type: goal, shot, missed shot, and blocked shot. It should be noted that missed and blocked shots have a 0% chance of being a goal. However, wSHOAG assumes the shot attempt was put on net. (In other words, if missed shot X had not actually missed the net, but was put on net, what is the probability that the shot results in a goal?). By weighting each shot-type by the goal probability, we can get a better picture of the overall discipline of an offense and opposing defense.
Weighted SHOAG rewards successes and penalizes faults. If a team has an equal number of shots on net as they do missed and blocked shots, and the shots on net are of better quality than those that are missed and blocked, wSHOAG increases. Contrarily, if a team’s missed and blocked shots have high goal probabilities (assuming they were put on net), wSHOAG decreases.
Consider two different teams: Team A and Team B. Let’s assume that Team A and Team B are playing against each other and have identical shooting stats through two periods of play. Each team has 1 goal, 22 shots on net, 10 missed shots, and 7 blocked shots. Both team’s SHOAG statistics are equal to 0.575 (Eq. 3).
Both Team A and Team B put the puck to the net 57.5% of the time. According to SHOAG, these teams are evenly matched. Let’s see what wSHOAG tells us. Each team’s expected goal stats are those provided in Table 1.
Table 1. Expected goals (EG) for exemplar Teams A and B
Respective wSHOAG statistics are given in Eq. (4) and (5):
That wSHOAG stats reveals characteristics of each team’s offense and defense. A smaller wSHOAG statistic (e.g., Team B) may indicate an offense that:
- commonly takes quality shots at net, but the collective quality (i.e., expected goals) of missed and blocked shots outweigh the expected goals of shots on net.
- is matched up against a defense efficient in blocking shots
- displays shot attempts of equal quality, but the sum of missed and blocked shots outweigh the sum of shots on net
A larger wSHOAG statistic (.e.g., Team A) may indicate an offense that:
- commonly takes quality shots at net, but the expected goals of shots on net outweigh those of missed and blocked shots
- a matchup against a defense inefficient in blocking shots
- an offense that displays shot attempts of equal quality, but the sum of of shots on net outweighs the sum of missed and blocked shots
The wSHOAG of Team A is almost .100 greater than that of Team B. Both teams displayed nearly equal expected goals for their shots on net, but Team B’s missed and blocked shots were of greater quality than those of Team A. Remember, wSHOAG rewards successes (good quality of shots on net) and penalizes faults (good shot quality of missed/blocked shots). This is seen in our example between Team A and Team B. What does this tell us? Team A allows Team B to take higher quality shots, but Team A is good at blocking these shots. In addition to having some high quality shots blocked, Team B also missed the net on what would have been quality shots had they been on net.