Non-Penalty Expected Goals
Non-penalty expected goals is a player's expected goals with penalties removed, since a spot kick is worth roughly 0.78 xG on its own.
Why it matters. It gives a truer read of open play threat, and it is essential whenever a penalty taker is being compared against a player who does not take them.
Why penalties get pulled out
A penalty is a shot from twelve yards with no defender and only the goalkeeper to beat. Its expected goals value sits close to 0.78, and that figure barely moves no matter who is standing over the ball. It is not a shot a player earned through movement. It says nothing about how they get into space in open play.
Leave penalties inside a player's xG total and two things happen at once:
- A designated taker's number inflates, sometimes by several goals worth of xG across a season, none of it related to their open play movement or finishing.
- A non-taker's number looks comparatively worse, even if their actual chance creation and movement is identical to the taker's.
Non-penalty expected goals removes the spot kicks entirely, penalty taken and shot value both. What is left is only what a player generated through open play and other set pieces.
npxG rewrites three verdicts
Two strikers, one number that is fair. Put a club's regular penalty taker next to a team mate who has never taken one. Their raw xG totals can diverge sharply, purely because of who stands over the ball on match day. Switch to npxG and the comparison becomes about movement and shot quality alone, which is the comparison most people are actually trying to make.
A finishing read that is not skewed. A striker's goals minus npxG, read alongside their goals minus xG, separates two different questions. The first asks how their open play finishing compares to the chances they created. The second folds penalty conversion into the same number, which can hide a real slump in open play behind a couple of converted spot kicks.
When the taker changes mid-season. A club changes penalty taker, and one player's xG jumps while another's drops, purely from a role swap that has nothing to do with form. npxG for both players holds steady through the change, because it was never measuring that part of their game.
Getting this wrong, and why
"A scored penalty stops counting." It does not. The goal still counts on the scoreboard and in the raw goals total. Only the shot's expected goals value comes out of npxG. That is exactly why a heavy taker can show a wide gap between actual goals and npxG without it reflecting anything about their open play finishing.
"npxG is the more accurate number, full stop." It answers a different question, not a better one. For judging open play movement and shot quality, npxG is the fairer comparison. For projecting a player's total season output, penalties they are actually likely to take are real and repeatable, and ignoring them underrates their expected return.
"It only matters for strikers." Wingers and midfielders can take penalties too, and the same distortion applies to them. Anywhere a raw xG total is being used to compare two players, checking whether one of them takes penalties is the first thing worth doing.
Common questions
- Why is a penalty worth about 0.78 xG?
- Because that is roughly the conversion rate of penalties across very large samples, regardless of who is taking it. The value barely moves with the taker, which is exactly why leaving penalties in flatters the regular taker over everyone else.
- Should npxG always be preferred to xG?
- For comparing open play threat, yes. For projecting a player's total output, no. If a player is their team's established taker, those chances are a real and repeatable part of what they produce, and stripping them out would understate what they are actually worth.
- Do missed penalties still count against npxG?
- No, in either direction. The whole penalty, scored or missed, is removed from the calculation. npxG is not affected by penalty conversion at all, only by what happened in open play and from other set pieces.
- Does npxG strip out the goal itself, or just the shot's xG value?
- Only the shot's expected goals value comes out of npxG. A scored penalty still counts as a goal on the scoreboard and in the raw goals column, which is exactly why a heavy penalty taker can show a large gap between goals and npxG without that gap meaning anything about their finishing.
- Does it also apply to team totals?
- Yes, the same logic scales up. A team's non-penalty xG for or against strips out spot kicks from either side, which matters for judging attacking or defensive quality independent of how many penalties were won or conceded that season.
Related terms
See npxG across the Premier League
Every player, team and match measured on the chances created rather than the scoreline.
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