How to Work Out the Stroke Index in Golf

Knowing you get strokes in a round is one thing, but figuring out how and where to use them is a different game entirely. The Stroke Index is the map that guides this process, yet for many golfers, it remains one of the most confusing columns on the scorecard. This guide will walk you through exactly what the Stroke Index is, how to find it, and most importantly, how to apply it step-by-step so you can play with total confidence in your next competition or friendly match.

What Exactly Is the Stroke Index?

In simple terms, the Stroke Index (often abbreviated as 'SI' or 'HCP' on a scorecard) is a ranking of the holes on a golf course from 1 to 18. The hole with a Stoke Index of 1 is rated as the most difficult on the course, while the hole with a Stroke Index of 18 is rated as the easiest.

It's important to understand this isn't just about length. Course raters determine this "difficulty" by considering many factors, including:

• Length: Longer holes are generally harder, but it’s not the only factor.
• Obstacles: The number and placement of bunkers, water hazards, and trees.
• Terrain: Uphill shots, severe slopes in the fairway, or challenging doglegs.
• Green Complexity: The size, slope, and undulation of the green. A small, crowned green can make a short hole incredibly tough.

The primary purpose of the Stroke Index is to create a fair and standardized a way to distribute handicap strokes. It ensures that a higher-handicap player receives their extra shots on the holes where they are most likely to need them. A common point of confusion for new players is mixing up the Hole Number with the Stroke Index. Just because you're on the 5th hole doesn't mean it has a Stroke Index of 5 - it might be the hardest hole on the course (SI 1) or the easiest (SI 18).

Your Guide to Using the Stroke Index

Let's move past the theory and into the practical application. Using the Stroke Index becomes second nature once you’ve done it a few times. It all starts with a simple formula to figure out how many strokes you get, followed by looking at the scorecard to see where you get them.

Step 1: Calculate Your Course Handicap

Before you can apply the Stroke Index, you need to know how many strokes you're entitled to for that specific course. This is your Course Handicap. While the official formula can look a little intimidating, the good news is that you rarely have to calculate it yourself. Most golf club computer systems, pro shops, or modern GPS/scoring apps will show your Course Handicap for the tees you're playing.

For those who are curious, the calculation is:

Course Handicap = (Handicap Index × (Slope Rating ÷ 113)) + (Course Rating - Par)

Don't worry about memorizing that. The key takeaway is that your handicap isn’t a fixed number, it adjusts based on the difficulty of the course you’re playing that day. For the rest of this guide, let's assume you've used a service a to find your Course Handicap for your round.

Step 2: Apply Your Strokes in Stroke Play (like Stableford)

Stroke play formats where handicaps are used, like net-score competitions or Stableford, are the most common places you'll see the Stroke Index in action. It’s a simple, two-part process.

Let’s say your calculated Course Handicap is 22.

1. How many strokes per hole? First, divide your handicap by 18. In this case, 22 ÷ 18 is 1, with a remainder of 4. This means you will receive at least one stroke on every single hole.
2. Where do the extra strokes go? The remainder (4) tells you how many extra strokes you get. You apply these extra strokes to the most difficult holes. You’ll get a second stroke on the holes with Stroke Index 1, 2, 3, and 4.

So, for your round:

• On holes ranked SI 1 through SI 4, you get TWO strokes.
• On holes ranked SI 5 through SI 18, you get ONE stroke.

A Second Example: Course Handicap of 14

If your Course Handicap is 14, it's even simpler because it's less than 18.

• You get ONE stroke on the holes ranked SI 1 a through SI 14.
• You get ZERO strokes on the holes in ranked SI 15 through SI 18.

Pro Tip: A great way to think about this is creating a "personal par" for each hole. If you’re playing a par-4 that is rated SI 2, and you have a Course Handicap of 14, you get a stroke. This means your personal par a for that hole is 5. If you make a 5, you've essentially made a "net par," which is great for your score.

Step 3: Apply Your Strokes in Match Play

This is where the Stroke Index truly shines and often feels most impactful. A In Match Play, you are playing head-to-head against another person, winning, losing, or halving each hole.

The process starts by comparing handicaps.

Let’s imagine a match between Player A and Player B.

• Player A's Course Handicap: 21
• Player B's Course Handicap: 13

1. Find the Difference: Subtract the lower handicap from the higher one. 21 - 13 = 8 strokes.
2. Assign the Strokes: The player with the higher handicap (Player A) receives these 8 strokes. The player with the lower handicap (Player B) plays off scratch (0) for the purposes of the match.
3. Check the Scorecard: Player A will receive one stroke on the 8 most difficult holes - those ranked SI 1, SI 2, SI 3, SI 4, SI 5, SI 6, SI 7, and SI 8.

Now, let's play a theoretical hole. The 4th hole on the course is a par-4 and has a Stroke Index of 7. Since Player A gets a shot on holes SI 1 through 8, a they have a shot here.

• Player A scores a 5 on the hole. Her "net score" is 4 (5 - 1 stroke).
• Player B scores a 4 on the hole. His "net score" is 4.

Even though Player A took one more shot, the hole is a Half. The stroke leveled the playing field a exactly as it was designed to do.

Putting S.I. Knowledge into Your On-Course Strategy

Understanding the Stroke Index isn't just about marking up your scorecard correctly, it's a powerful strategic tool that can change how you approach the entire course. It removes pressure on hard holes and sharpens your focus on easier ones.

Embracing the "Shot"

When you're standing on the tee of a long, difficult par-4 with water on the left and bunkers on the right - the kind of a hole that makes your palms sweat - check the Stroke Index. If it’s SI 1 or 2 and you get a stroke, your mindset can instantly change.

Instead of feeling pressured to hit a perfect drive and a heroic long-iron into the green, you can adopt a safer strategy. Your goal is a bogey (a net par). You might decide to hit a 3-wood off the tee for accuracy, lay up short of the green with you your second shot, and rely on a simple chip and two putts. You can make a 5 with far less risk and still walk away feeling like you've won the battle.

Respecting the "Scratch" Holes

Conversely, look at the holes with a high Stroke Index, like 17 or 18. These are the holes where you don’t receive a stroke. You are playing on level terms with every other golfer. These are often shorter par-4s or par-3s and represent your best opportunities to score.

Knowing this ahead of time helps focus your mind. These aren't the holes for taking unnecessary risks. You want to prioritize finding the fairway and hitting the green a because a par here is a real par, and it feels like picking up a shot on the field. The Stroke Index tells you a where your scoring opportunities lie.

Final Thoughts

The Stroke Index is the engine that makes handicap golf work. By understanding that it’s a ranking of difficulty from 1 (hardest) to 18 (easiest), you unlock the ability to correctly apply your strokes, level the playing field in matches, and craft a smarter on-course strategy. It transforms the numbers on a scorecard from a confusing list into a clear roadmap for your round.

I know this can still feel like a lot to manage on the course when you're also thinking about your swing and reading putts. This is precisely why we designed Caddie AI. The app automatically calculates your hole-by-hole strategy by factoring in your handicap and the Stroke Index, so you don't even have to think about it. It just tells you the smart play, taking the mental calculation off your plate so you can focus on hitting a great shot with confidence.