ESR and Gr

Beyond Save Percentage: Why GR and ESR Matter

For years, goalies have been judged primarily by two familiar numbers: save percentage and goals-against average (GAA). Those stats are useful, but they only describe the end result. They miss the context of what the goalie was actually dealing with.

Save percentage tells you the proportion of shots a goalie stopped. GAA tells you how many goals they allowed per game. Neither says anything about the kinds of shots faced, how dangerous those chances were, where they came from, or how difficult each save really was.

That gap is what the 3xG system is designed to address.

A goalie handling a steady diet of clean point shots is playing a very different game than a goalie facing backdoor passes, rebounds, traffic, rush chances, and high-danger slot looks. Traditional stats treat those environments almost the same. GR and ESR do not.

What ESR Measures

ESR stands for Expected Save Rate.

ESR estimates how saveable a shot is expected to be for a goalie based on the specific context of that shot. It is expressed on a 0 to 1 scale, where 0.5 represents an average expected save difficulty.

• A higher ESR means the shot is expected to be easier to save.
• A lower ESR means the shot is expected to be more dangerous and harder to stop.

ESR is built from the information tracked within 3xG, including:

• shot location on the ice
• net location of the puck
• goalie crease position
• pass origin, when applicable
• game situation context

Instead of only asking, “Was it saved?” ESR asks, “How saveable was this shot expected to be given the situation?”

What GR Measures

GR stands for Goalie Rating.

GR evaluates how the goalie performed relative to the difficulty of the shots they faced. Like ESR, it is measured on a 0 to 1 scale, with 0.5 representing average performance.

• A GR above 0.5 means the goalie performed above expectation.
• A GR below 0.5 means the goalie performed below expectation.

In simple terms:

• ESR measures shot difficulty.
• GR measures goalie performance against that difficulty.

When a goalie stops a difficult, low-ESR shot, their GR rises more than it would for a routine stop. When they allow a goal on a higher-ESR, lower-danger shot, GR reflects that as well.

Why This Goes Beyond Save Percentage and GAA

Save percentage and GAA are outcome-based statistics. They tell you what happened, but they are heavily influenced by factors around the goalie: team play, defensive structure, shot quality, and overall game environment.

GR and ESR inject the missing context.

They help coaches and goalies answer more precise questions, such as:

• Was the goalie consistently facing dangerous chances?
• Were the goals coming from high-quality scoring areas?
• Did the goalie outperform the expected difficulty of the shots?
• Are training or tactical focuses showing up in specific game situations?
• Is performance improving in the areas that matter most for this goalie?

This shifts evaluation from broad, team-influenced results to contextual, goalie-specific performance.

How the GR and ESR Formula Works

The process starts by assigning each shot a difficulty score using the data captured in 3xG.

The model combines key pieces of shot context, including:

• where the shot originated on the ice
• where the puck was placed on net
• the goalie’s position in the crease at release
• whether there was a pass origin leading into the shot
• the game situation at the time of the shot

Those details are merged into a single ESR value for each shot, representing how saveable that shot is expected to be.

GR then layers in the shot result:

• If the shot is saved, the goalie’s rating increases, scaled by how difficult the shot was expected to be.
• If the shot becomes a goal, the goalie’s rating decreases, scaled by how saveable the model expected that shot to be.

A goalie’s game-level GR is built from this shot-by-shot evaluation over the course of the game.

Why This Approach Is Different

GR and ESR only become possible because 3xG captures goalie-specific information at a depth traditional stat systems do not. Without context such as detailed shot location, net placement, pass data, and situation tagging, every shot looks too similar for meaningful evaluation.

With 3xG, those details turn into usable performance intelligence.

That is what sets GR and ESR apart. They are not just fresh numbers on a stat sheet; they are a new framework for understanding goalie performance through the lens of shot difficulty and context—the lens the position has always needed.

For goalies and coaches, that means clearer feedback, more targeted development, and a truer picture of how well a goalie is really playing.