{"metric":{"id":"npxgd","name":"Non-penalty xG difference","short":"npxGD","level":"side","unit":"xG per match","tier":"flagship","summary":"How many more (or fewer) non-penalty xG a side creates than it allows, per match (each match counts as 90 minutes).","definition":"For every league match of a side: the non-penalty xG of its shots minus the non-penalty xG of its opponent's shots. A season's npxGD is the mean over the side's matches, which is the same as per 90.","inputs":["The shots of both sides of every league match since 2014-15, with 11footy xG.","The league and the season of the match; nothing from the table or the result."],"formula":["npxGD per match = (non-penalty xG for - non-penalty xG against) / matches.","A side at +0.50 creates half a goal more than it allows in an average match."],"readings":[{"name":"npxG for","what":"per match, penalties left out"},{"name":"npxG against","what":"per match, penalties left out"}],"sample":["A side's number is ranked from 15 league matches; under that it is marked provisional.","The check below uses full seasons only (30+ league matches).","Compared within a league and season; the numbers of different leagues are not adjusted to each other."],"limits":["The score changes how sides play: a side that leads sits back and creates less. The number is not adjusted for that, nor for the strength of the opponents.","Numbers of different leagues and seasons are not adjusted to each other.","Only the chances that are shots: no possession, pressing or defensive shape enters.","It rests on 11footy xG, with the limits of the xG metric."],"shown_in":[{"label":"Team explorer: npxGD per match","href":"/lab/teams"},{"label":"Competition pages, Expected table: npxGD/90","href":"/competitions"},{"label":"Team pages","href":"/teams"}],"page":"/lab/metrics/npxgd","validation":{"stability":{"team_seasons":1150,"pairs_next":886,"seasons":[2014,2025],"min_matches":30,"rows":[{"key":"npxgd","label":"npxGD (11footy)","split_half":0.7588,"whole":0.8629,"to_second_half":0.7824,"to_next_season":0.7763},{"key":"xgd","label":"xGD, penalties in","split_half":0.748,"whole":0.8559,"to_second_half":0.7746,"to_next_season":0.7762},{"key":"gd","label":"Goal difference","split_half":0.6838,"whole":0.8122,"to_second_half":0.7453,"to_next_season":0.7612}]}},"validation_says":["Over 1,150 full team-seasons, the even matches and the odd ones agree at r = 0.76 for npxGD against 0.68 for goal difference.","The first half of a season's npxGD correlates 0.78 with its second half's goal difference against 0.75 for the first half's goal difference."]},"data":{"built_at":"2026-10-13T08:50:47Z","data_through":"2026-10-12T19:00:00Z"},"min_minutes":900,"small_minutes":450,"rule":"Every number here is computed by 11footy from base data (results, line-ups, minutes, shots). A provider's own derived metrics are not read anywhere."}