Corsi Against, Fenwick Against, and Expected Goals Against: How to Actually Evaluate an NHL Defenseman

Move beyond unreliable plus/minus stats to accurately evaluate NHL defensemen using advanced metrics like Corsi Against, Fenwick Against, and Expected Goals Against. These metrics measure shot suppression volume, shot quality, and the effectiveness of shot blocking to provide a clearer picture of defensive performance.

Marco Moretti

October 18, 2026 · 5 min read

Plus/minus will lie to you about a defenseman. It gets dragged around by goaltending and shooting luck, and it tells you almost nothing about what a blueliner did to shape the game. Three "Against" metrics — Corsi Against, Fenwick Against, and Expected Goals Against — fix that. Each one counts what happens at the defensive end while the player is on the ice, and each answers a different question: how much offense did he allow, how much of it actually got through, and how dangerous was it?

Beyond Plus/Minus: Why Traditional Stats Fall Short

Plus/minus measures goals for and against at even strength, which sounds fair until you consider what a single player controls. A defenseman can be beaten cleanly, have his goalie bail him out, and finish the night plus-2. Or he can play airtight hockey behind a goalie having a bad month and sink to minus-5. The stat absorbs outcomes the player didn't produce.

Shot-attempt differentials were built to solve this. Charlie O'Connor, writing in The Athletic's advanced stats primer, laid out the classic case: a team that is +50 in shot attempts over twenty games but has been outscored by ten is, per the research he cites, more likely to post a positive goal differential over the next sixty games, because it "drives play." That's why a player with a great plus/minus but an awful Corsi is generally expected to regress. Goals are noisy; the process that generates them is not. Raw on-ice numbers still carry context problems — Evolving-Hockey notes that teammates, opponents, and zone starts all distort them — but shot-based metrics are the foundation that more sophisticated models build on.

Choosing the Right Defensive Metric: A Decision Framework

The three metrics are not competitors; they're a funnel, narrowing from all activity to genuine danger. Use this matrix to match your evaluation question to the right stat:

Decision framework for NHL defensive metrics (even strength)
Metric	What It Counts	Best Used For
Corsi Against (CA)	All opposing shot attempts: shots on goal, misses, and blocks	Overall shot suppression and territorial control — is this defenseman limiting the opposition's offensive activity at all?
Fenwick Against (FA)	Unblocked attempts only: shots on goal and misses	Whether attempts actually reach the net — useful for judging shot-blocking schemes and defensemen on teams that trade volume for blocks
Expected Goals Against (xGA)	Each attempt weighted by its goal probability (location, type, situation)	Limiting high-quality chances — did he prevent dangerous opportunities, not just shots?

Read the rows in order and you get a diagnostic sequence. High CA with low xGA suggests a defenseman allowing volume but little danger. Low CA with high xGA suggests the opposite: few chances, but the ones that get through are dangerous. Fenwick sits between them, revealing whether blocks are doing real work.