Strokes gained

Strokes gained measures every shot against a baseline: how many strokes a reference golfer would expect to need from where you stood, versus where your shot left the ball. Hit it closer than the baseline expects and you gain a fraction of a stroke. Leave it short or in trouble and you lose one. Add those fractions up and you get a number that says, in strokes, how much each part of your game helped or hurt.

The core formula

For a single shot:

strokes gained = expected strokes (before the shot)
               − expected strokes (after the shot)
               − 1

The "− 1" is the shot you just played. If you had 2.98 expected strokes from 160 in the fairway and finished with 1.84 expected strokes (15 feet on the green), you gained 2.98 − 1.84 − 1 = +0.14. You did slightly better than the baseline.

A holed shot ends at 0 expected strokes, so it can produce a large positive number. A shot into trouble raises the expected strokes after, which produces a negative number.

The baseline is built around your handicap

GSCaddie does not use one fixed tour baseline. It stores two anchor curves of expected strokes per lie:

• A scratch curve (handicap 0).
• A bogey curve (handicap 18).

For your handicap, it blends linearly between the two. A handicap of 9 sits halfway between the curves. Anything at or above 18 uses the full bogey curve.

This matters because the two curves differ in shape, not just height. An amateur loses far more around the green and on long approaches than off the tee, so the per-shot adjustment changes with the lie and distance. The bogey curve was calibrated to a realistic mid-handicap scoring average (a bogey golfer shooting in the 90s), so a player who plays to their handicap totals roughly zero strokes gained for the round rather than a large artificial loss.

Expected strokes are looked up by lie and distance. Distance is in yards for every lie except the green, which is measured in feet. The curves cover these lies: tee, fairway, rough, sand, recovery, and green. Sand and bunker both map to the sand curve, deep rough folds into rough, and an unknown surface is treated as fairway.

The four categories

Every non-putt shot is bucketed into one of four categories. The bucket is decided by where you were before the shot (the context in which you chose the club), not where the ball landed.

Putting is excluded from the total

Putting strokes gained always evaluates to 0 in GSCaddie. Simulator putting (especially auto-putt) does not behave like a real putting stroke against the tour putting baseline, so counting it would distort the number. Raw putt counts are the honest putting signal instead. Because putting collapses to 0, your strokes gained total is effectively a tee-to-green figure: the sum of off-the-tee, approach, and around-the-green.

How a hole is finished

For the last shot on a hole to be scored as a hole-out (expected strokes after = 0), it has to actually finish the hole. A shot counts as holed when it is flagged holed out, or when the final shot of the hole is a putt, or when it finished within gimme range of the pin. Otherwise the data just ends there (a ball picked up, or a partial mid-round hole) and the shot is not credited as a hole-out.

Display reconciliation

The four category numbers are an exact decomposition of the total: the same per-shot sum, just bucketed. But rounding each tile to two decimals on its own can leave the visible tiles a penny off the headline (for example tiles summing to −13.63 under a −13.64 total). GSCaddie re-rounds the categories so they add up exactly to the rounded total, parking the leftover cent on the largest-magnitude category where it is least noticeable. The headline total itself is never adjusted, so it stays consistent across the dashboard, history, and round overview.

It is an estimate

Strokes gained here is a model, not a measurement. The baseline curves are derived from published amateur and tour benchmarks and are still being calibrated against real data. Shots that are missing a distance-to-pin or a surface lie cannot be scored at all, so a round reports its SG coverage (the fraction of shots that had the inputs). For how shots get excluded and flagged, see excluded shots and data quality. For the raw fields the baseline reads, see the data dictionary.