What Is Personal SI? Your Personal Stroke Index

The Stroke Index printed on a scorecard is the same for everyone. Your golf is not.

You may consistently play a hole marked SI 2 well, while repeatedly losing shots on a hole marked SI 14.

Personal SI uses your own scoring history to show that difference.

Instead of assuming the holes printed with the lowest Stroke Index numbers are your biggest problems, 4LEFT looks at what actually happens when you play them.

Not exactly.

Golfers commonly use Stroke Index as shorthand for hole difficulty — SI 1 is often described as the hardest hole and SI 18 as the easiest.

But the official Stroke Index also has an important role in allocating handicap strokes around the course, so it is not simply a personalised hardest-to-easiest ranking.

Personal SI is different. It is deliberately personal. It asks:

Where does this golfer actually lose the most shots?

4LEFT looks at your recorded hole-by-hole scores on a course.

For each hole, it measures your average scoring cost relative to par across the rounds in the relevant scoring sample. For example:

• averaging 5.4 on a par 4 = +1.4 shots
• averaging 4.8 on a par 4 = +0.8 shots
• averaging 3.6 on a par 3 = +0.6 shots

4LEFT then compares the holes and orders them according to that personal scoring cost. The hole currently costing you most becomes Personal SI 1. The hole costing you least becomes Personal SI 18.

The calculation uses an evidence-controlled sample of your recorded rounds. 4LEFT can also restrict the comparison to an appropriate handicap range so that golf from a materially different stage of your playing ability does not automatically dominate the result.

Personal SI 1 means that, within the scoring evidence 4LEFT is analysing, this is currently the hole costing you the most shots relative to par.

It does not mean the hole is objectively the hardest hole on the golf course.

Another golfer may have a completely different Personal SI 1. That is the point.

Personal SI describes your scoring, not everybody else's.

Personal SI 18 is currently the least costly hole in your personal scoring history on that course.

That can be useful information too.

A hole that looks intimidating on the scorecard may actually be one you repeatedly handle well.

That is evidence of scoring resilience rather than a problem that necessarily deserves more practice attention.

That disagreement is often the most useful part.

Imagine:

Club SI 2 → Personal SI 15

The scorecard gives the hole a low Stroke Index and golfers may naturally think of it as one of the tougher holes. But your own scoring repeatedly holds up well there.

That is evidence of high personal resilience on that hole.

Now imagine:

Club SI 14 → Personal SI 2

The card does not draw much attention to the hole. But your own scoring says it is one of your biggest sources of lost shots.

That is a hole worth investigating.

The difference between Club SI and Personal SI can therefore challenge assumptions about where your round is really being won or lost.

Resilience means that your scoring consistently holds up on a hole.

It is not a separate hidden score or coefficient in the current Personal SI calculation. Instead, it is an interpretation of your repeated scoring performance, especially when that performance is compared with the course's published Stroke Index.

If you repeatedly handle a hole well despite its low Club SI, your scoring is showing resilience there.

If a relatively unremarkable-looking hole repeatedly becomes expensive for you, your scoring is showing less resilience there.

Personal SI helps make that contrast visible.

Not automatically.

Personal SI tells you where to investigate first. It does not, by itself, tell you why the hole is costly.

That is where the rest of your 4LEFT data becomes useful. For example:

• missed fairways may point towards tee-shot strategy
• low greens in regulation may point towards approach play
• good GIR but high putts may point towards putting
• repeated doubles or worse may suggest damage limitation or course management
• no obvious statistical pattern may suggest looking more closely at decision-making or pre-shot routine

Personal SI identifies the hole. Your round data helps explain the reason.

Sometimes Personal SI tells you what not to worry about.

Suppose a hole is Club SI 3 but Personal SI 16. Your scoring evidence says you repeatedly handle that hole well.

Rather than concentrating practice or mental energy there simply because the scorecard makes it look difficult, you may be better treating it as a hole you already manage successfully.

In simple terms: bank it.

Then direct more attention towards the holes where your own scoring evidence shows a genuine problem.

Yes.

Two golfers can play the same course from the same tees and have very different Personal SI rankings.

One golfer might struggle with long par 4s. Another may handle those holes well but repeatedly lose shots on short approaches or around certain greens.

The course is the same. The scoring problems are not.

Personal SI is designed to expose those individual differences.

No.

Personal SI is an analysis tool. It does not alter:

• your official Handicap Index
• your 4LEFT Handicap
• Course Handicap
• Playing Handicap
• the Stroke Index printed on the scorecard
• handicap strokes in a competition

Personal SI helps explain where your scoring is being lost. It is not a handicapping calculation.

No.

Personal SI is a proprietary 4LEFT concept produced using 4LEFT's SPAR methodology. It is not part of WHS and is not an R&A, USGA or England Golf measure.

The term “Stroke Index” is used because Personal SI gives each hole a personal 1–18 ordering. It should not be confused with the official Stroke Index used for handicap-stroke allocation.

Personal SI becomes more informative as 4LEFT collects more hole-by-hole evidence for the course.

A small number of rounds can provide an early signal. More rounds make it easier to see whether the pattern persists.

4LEFT therefore distinguishes between developing evidence and a more established Personal SI rather than presenting every early ranking as equally certain.

You should treat a new Personal SI as something to investigate, not as an unquestionable verdict on the hole.

No.

4LEFT uses a controlled sample of relevant scoring history rather than treating every round you have ever played as equally representative forever.

The current methodology applies a limit to the scoring history used and can filter rounds according to the golfer's handicap regime.

That helps avoid comparing current golf indiscriminately with rounds played when the golfer's ability was materially different.

There is no separate recency weighting inside the current Personal SI ranking.

Yes.

Personal SI reflects the scoring evidence available to 4LEFT.

As more rounds are recorded, the average scoring cost of individual holes can change and the 1–18 ordering can move.

A problem hole can become less costly. A previously reliable hole can begin causing trouble.

That is useful because the analysis can change with the golfer rather than becoming a permanent label attached to a hole.

The hole you thought was difficult

Imagine Hole 4 is Par 4 — Club SI 2. You expect it to be one of the holes that damages your card.

But across your recorded rounds your scoring cost is relatively low compared with the rest of the course. 4LEFT gives it Personal SI 15.

For you, this is not currently one of the major problems. Your scoring repeatedly holds up. That is resilience.

The hole hiding in plain sight

Now imagine Hole 11: Par 4 — Club SI 14. It does not look particularly threatening when you glance at the card.

But your own scoring history repeatedly shows a higher scoring cost there than on most of the course. 4LEFT gives it Personal SI 2.

That is useful information. Rather than spending practice attention on the holes you assume are difficult, Hole 11 becomes somewhere worth investigating.

The next question is: why? That is where fairway, GIR, putting and round-analysis information can add context.

Start with evidence rather than immediately changing your swing or club selection.

Look at what your recorded rounds show. Ask:

• Am I regularly missing the fairway?
• Am I reaching the green in regulation?
• Am I taking too many putts?
• Are doubles or worse common?
• Is one part of the hole repeatedly causing the problem?
• Am I making the same strategic decision every time?

A different tee club, different target or different pre-shot approach may eventually make sense.

But Personal SI alone should not prescribe that change. It tells you where the problem is showing up.

One round can be noisy.

A 7 on a hole yesterday does not necessarily make that hole a persistent weakness.

Personal SI uses scoring history across multiple rounds to look for the underlying pattern.

That makes it different from a post-round list of where you happened to drop shots that day.

The most useful question is not:

“Where did I have a bad hole?”

It is:

“Which holes keep costing me?”

SPAR is the methodology. Personal SI is the golfer-facing output.

SPAR — Scoring Performance & Resilience — analyses your personal scoring evidence.

Personal SI turns that evidence into a simple 1–18 ordering of the holes.

How SPAR works →