Per game vs per opportunity: why both matter

Two running backs finish a game with 80 rushing yards. In the box score, they look level. Then you notice that one needed twice as many carries. That extra detail changes what you can learn from the result.

A per-game average describes output across games. A per-carry average describes output across carries. Neither replaces the other: one helps you understand the total contribution, while the other helps explain how the player got there.

Think of the unit as part of the number's name. “80 yards per game” and “8 yards per carry” aren't two scores on the same scale. You can compare players within either measure, but you can't compare 80 directly with 8.

Runner A has 80 rushing yards on 10 carries. Divide 80 by 10 and you get 8 yards per carry. Runner B has the same 80 yards on 20 carries, so 80 divided by 20 gives 4.

The total is equal; the average gain on a carry is different. That is all the example establishes. A's average could reflect several long runs, while B's could reflect many steady gains. The average doesn't show the individual runs.

Don't translate this into a promise about the next game. Ten carries at an observed eight yards per carry doesn't mean every future carry is worth eight yards. The opponent, situations and individual gains can all change.

Now follow Runner A across two games. The first has 80 yards on 10 carries. The second has 20 yards on 10 carries. Together that's 100 yards on 20 carries: 5 yards per carry, and 50 yards per game.

If the carry counts were different, giving each game's rate equal weight could mislead you. A two-carry game shouldn't influence a pooled per-carry rate as much as a twenty-carry game just because both occupy one row.

Keep player appearances visible too. A player who missed a team game didn't necessarily record a zero-yard performance. Check whether a displayed average counts games they played or all team games.

When reading a player report, start with three pieces: how often they played, how many opportunities they received, and what they produced. A strong rate on a tiny workload is interesting, but it tells a different story from the same rate over sustained volume.

The opportunity has to match the statistic. Receiving yards per target and receiving yards per catch answer different questions, because an incomplete target doesn't become a catch. Baseball hits per at-bat also differ from hits per plate appearance.

A clear takeaway might be: “Both runners had 80 yards, but A did it on ten carries and B on twenty.” That's more useful than choosing the larger-looking number without reading its unit.