Everything you might be wondering

OpenSG (Open Strokes Gained) is a golf app that tracks every shot of your round by GPS and shows you exactly where you gain and lose strokes — off the tee, on approach, around the green, putting and penalties — measured against the level you choose: your own handicap, scratch, or PGA Tour average. While you play it doubles as a caddy, and for teams it becomes a coach's dashboard. Strokes Gained is the same stat the tours use to analyze performance; OpenSG puts it in your pocket.

Strokes Gained measures each shot against how a benchmark golfer would score from the same spot. Every position on a course has an expected number of strokes to hole out. For one shot, your Strokes Gained is:

(expected strokes where the ball started) − (expected strokes where it ended) − 1

That “− 1” is the stroke you just took. Beat the benchmark and you gain a fraction of a stroke; come up short and you lose one. Add up every shot in the round and you get your total, split into five categories — Off-the-Tee, Approach, Around-the-Green, Putting and Penalty — so a hot putter can't hide a cold approach. You choose the benchmark: Their Handicap (a golfer of your index), Scratch, or PGA Tour average.

OpenSG shows you two numbers, because they answer different questions:

• Estimated handicap — a traditional, GHIN-style index computed from your recent scores against course and rating. It's the familiar number other golfers use.
• OpenSG handicap — an SG-native index built from how many strokes you gain or lose against scratch, averaged over your better rounds. Because it's built from every shot rather than just the final score, it settles faster and is harder to fool with one lucky or unlucky round.

Both are estimated from your OpenSG rounds and get more accurate as you log more. When you pick the “Their Handicap” benchmark, OpenSG uses a conservative, gated version of your index so a handful of early rounds don't swing it around.

OpenSG is free for everyone while we're in beta — no card required to start. Our plan after beta:

• Off-course practice stays free, always.
• On-course, real-round tracking moves to an affordable subscription — monthly or annual options for individuals.
• Teams and organizations pay a plan priced by roster size.
• Students linked to a coach or team play for free — the coach's plan covers them.

Final prices are announced before the beta ends. Nothing you track today is locked behind a future paywall.

Three ways, and you can mix them freely:

• Automatic (GPS). The app follows your ball by GPS and drops each shot for you — you just confirm at the hole with a tap. This works best in the native app, which can read GPS in the background as you walk.
• Manual. Tap to place a shot yourself, any time.
• Post-hole reconstruction. At the end of a hole (or the whole round) a visual editor lets you drag, add or re-club any shot on the map. GPS breadcrumbs help you recover shots you forgot to log, and lies are detected automatically from the course map.

You never have to stand over the ball fiddling with your phone — capture stays out of your way, and you can always fix it afterward.

Playing a round works fully offline. Once a round has started, everything you need is on your phone, so you can play a course with no signal and it syncs automatically when you're back online.

Features that pull live data need a connection: course search, live weather and wind, green contours you haven't already downloaded, and the coach dashboards.

Live, over-the-ball tools while you play:

• Plays-like distance & suggested club on every shot — adjusted for slope, wind and altitude.
• Expected strokes (eS) — the expected score to hole out from any spot on the course.
• Outcome odds — pick a target and see the chance of finishing in the fairway, rough, water or out of bounds, based on your real dispersion.
• Green read — an aim line and break for the putt, from green contours.
• Your dispersion drawn on the hole, live weather, satellite maps, and per-hole yardage-book notes with aim lines and “don't-hit” markers.

Tournament mode switches the app to a Rules-of-Golf-legal view for competition. It hides the assistance the Rules don't allow during a round — club suggestions, plays-like and slope adjustments, green reads, outcome odds, and the practice tools — leaving only what's permitted: raw linear distances, your map and your notes.

It's a one-tap switch, so you can lean on the full caddy for casual rounds and stay compliant when it counts. Coaches can also lock a scheduled event to tournament mode.

Your golf bag holds your clubs and their real distances, learned from the shots you actually hit — not a generic yardage chart. OpenSG also learns your dispersion: how far your shots spread, described by a standard deviation (how tight the pattern is) and a shape (whether you tend to miss long/short or left/right).

That real spread is what powers the club suggestions, the shot pattern drawn on each hole, and your outcome odds. The more you play, the sharper it gets.

Partial swings let you record more than one distance for a club. You can add a partial swing to any club and name it however you like — “¾”, “half”, “9 o'clock”, whatever you call it — then enter the distance you carry that swing. A club only lists a partial swing once you've given it a distance, so you list only the ones you actually use. They're most useful for wedges, and for taking a few yards off a full swing when the full number is between clubs.

Alternative clubs surface a second way to play the same shot. Instead of a full 7-iron, for example, the caddy might show that a partial 6-iron covers the same distance — so you can pick the shot that fits the lie, the wind, or your confidence, not just the one club the number points at.

Normally the caddy adjusts your club distances automatically for altitude, temperature, wind and slope as you play. But in tournament mode the caddy is turned off, since the Rules don't allow that kind of live assistance during a round.

The Rules do let you use pre-calculated distances, and that's what a calibration is for. Before an event you save a calibration for the altitude and temperature you'll be playing in (a mountain trip, a cold morning), which tunes your whole bag once and stores it as a named preset. On top of that you use static adjustment charts for wind and slope — and those charts are themselves scaled to your calibration when the match starts, so every number stays consistent.

OpenSG has an off-course practice family: a virtual driving range, scored games (par-3, approach combine, green rotation), a simulator that lets you play a real course from the range, putting and green-reading drills, and a course-management simulator. Many are scored on Strokes Gained, so you can measure practice instead of just hitting balls.

Practice SG is kept completely separate from your real-round SG. It never touches your handicap, your stats page, or your benchmarks — practice lives in its own ledger. The one bridge is an optional per-category comparison you turn on yourself.

Point the app at the pin and it shows an aim line and the break for your putt, built from green contours. Contours come from a crowd-built database and, on supported devices, precise LiDAR scans — so reads get sharper over time. On tricky greens you can choose between candidate break lines.

A coach account adds a web dashboard the player app doesn't have:

• Your whole roster ranked by category Strokes Gained.
• A read-only deep dive on any player — both handicaps, every SG category, fairways, penalties and range sessions in one view.
• Coach-authored training recommendations and scheduled drills that land on a player's phone with a one-tap Start.
• Team and group analysis, a best-lineup optimizer with predicted scores for match day, course-fit ranking for a specific course, and event scheduling for qualifiers and matches.

What makes it different: it's built on real Strokes Gained from every shot — not just scores — and it adds no extra work for players (a coach view reads the same data players already log). It runs in any browser, so you can coach from a laptop or tablet.

Any OpenSG account can become a coach account — and you can still play yourself. From there you invite players by link, QR code or email; each player explicitly accepts (double opt-in) before you can see anything, and either side can disconnect at any time.

The fastest way to get going is a team pilot: a dashboard for your whole roster and OpenSG for every player. Request a team pilot and we'll help you onboard.

Today OpenSG runs as a native iPhone app (heading to the App Store), which is where the automatic background-GPS tracking works best. A web version runs on any modern phone browser, and coach dashboards work on any device — laptop, tablet or phone. A native Android app is coming a little later.

Everything core works without special hardware — just the phone in your pocket. Advanced sensors (LiDAR green scanning) need a compatible iPhone.

Safety for younger players is built in, not bolted on:

• We don't target minors with advertising.
• We block one-to-one messaging entirely — a coach can only post one-way announcements to a team of several players, never a private DM.
• Accounts have an age gate; under-14 accounts are blocked.
• Minor players (14–17) can have a guardian linked for read-only oversight and consent — the guardian approves connections while the player operates their own account.
• Coaches connect only to players who explicitly accept, and access can be revoked at any time.

Full details are in our Privacy Policy.