What Happens if a Golf Ball Hits Another Ball on the Green?

It’s a heart-sinking moment on the putting green: you’ve stroked a beautiful putt, it’s tracking perfectly to the hole, and then... click. Your ball collides with another player’s ball. Knowing the rule for this situation is essential, as what happens next depends entirely on the format you’re playing - and one outcome can add costly penalty strokes to your score. This guide will walk you through exactly what to do, covering the different rules for stroke play and match play, and providing simple etiquette tips to prevent this from happening in the first place.

The First Question: Stroke Play vs. Match Play?

Before you can figure out what happens next, you have to know what kind of game you’re playing. On the PGA Tour, in a club championship, or just your weekly league, nearly every ruling depends on whether it’s stroke play or match play. The consequence of hitting another ball on the green is one of the most glaring examples of this difference.

• Stroke Play: This is the most common format for most golfers. Everyone plays their own ball, keeps track of every shot, and the player with the lowest total score at the end of the round (or tournament) wins. Your goal is to get the lowest score possible on every hole.
• Match Play: This is a head-to-head competition. You’re not trying to beat the entire field, you’re trying to beat one specific opponent on a hole-by-hole basis. You win a hole by taking fewer strokes than your opponent. The final result is not a number like 78, but rather a score like "3 & 2," meaning you were 3 holes up with only 2 holes left to play.

The rules for hitting another ball on the green are completely different between these two formats. Understanding which you are playing is the very first step.

What Happens in Stroke Play (The One with the Penalty)

Stroke play is where this little accident can hurt. The rule is designed to penalize a player for not ensuring the playing surface was clear before they made their stroke on the green. It encourages good etiquette and active communication among players.

Scenario: Your Putt Hits Another Player's Ball on the Green

Let's paint a picture. You and three others are playing a friendly round but keeping score (stroke play). Everybody is on the green. You step up to your 20-foot putt, but another player's ball is resting near the hole, not on your intended line. You stroke the putt, but you misread the break badly. Your ball careens sideways and strikes their ball. What now?

According to Rule 11.1a of the Rules of Golf, the answer is clear and painful:

1. You (The Putter) get a two-stroke penalty. This is a general penalty for playing a ball from the putting green that then hits another ball also on the putting green. After the collision, you must play your ball from wherever it comes to rest. There’s no re-playing the shot.
2. The Other Player (Owner of the Stationary Ball) has no penalty. However, they must replace their ball on its original spot. If the original spot is not known exactly, it must be estimated. They cannot choose to play it from its new position.

So, in our example, that 20-foot putt just became incredibly expensive. The two strokes you took for the original putt are now saddled with two penalty strokes. What might have been a two-putt par has suddenly become a four-putt double bogey. It’s a harsh but straightforward rule designed to encourage players to mark their balls.

The Nuance That Saves You: Was Your Stroke Made from ON the Green?

Here’s a small but significant exception that can save you from the two-stroke penalty. The penalty only applies when the stroke causing the collision was made *from the putting green*. If your stroke was made from off the green, the rule changes completely.

Scenario: Your Chip from Off the Green Hits a Ball on the Green

Imagine this time you missed the green and are chipping from the fringe or the fairway. You hit a nice chip that lands on the green and starts rolling toward the hole, but before it can get there, it strikes another player’s ball that was already at rest on the green.

In this case, here's the outcome:

• You (The Chipper) receive NO PENALTY. You continue to play your ball from where it came to rest after the collision.
• The Other Player still has no penalty and must replace their ball on its original spot (or its estimated spot).

This is a big relief. The reasoning is that you have less control when playing from off the green, and it's considered reasonable for players on the green to mark their ball to protect the field. Hitting the ball from the fairway into an unmarked ball on the putting surface is just considered a "rub of the green," or part of the normal course of play.

What Happens in Match Play (The Forgiving Format)

If you're engaged in a match play battle, the rules are much simpler and more forgiving. The game is about you and your opponent, and the officials who write the rules have decided that this particular incident doesn’t need a penalty to keep things fair.

If Your Putt Hits Your Opponent's Ball

Let's say it's you versus one opponent. Both of you are on the putting green. You go to putt, and just like in our stroke play example, your ball hits your opponent's stationary ball.

According to Rule 11.1a, under match play exceptions:

• There is no penalty to anyone. You simply play your ball from where it came to rest.
• Your Opponent has a choice. They can either replace their ball to its original spot or, if they like the new spot better, they can choose to play it from where your ball knocked it.

Strategic Considerations in Match Play

This "player's choice" rule for the opponent adds an interesting layer of strategy to match play. It’s their decision, and they will always make the choice that benefits them most.

• Getting Knocked Closer: If your putt accidentally knocks your opponent's ball from 6 feet away to 6 inches, they will obviously choose to leave it in its new, much easier position. You just did them a huge favor!
• Becoming a Backstop: If you knock your opponent’s ball to a spot behind the hole, they might also choose to leave it there. Why? Because now, if their putt is too aggressive, your ball can act as a backstop and prevent theirs from rolling far past the cup.
• No Real Advantage: Most of the time, the ball will be knocked to a random spot that is no better or worse. In these cases, your opponent will almost always choose to replace it on the original marked spot.

The bottom line in match play is you don’t need to panic about the penalty, but you might have just helped your opponent! It's one of the quirky facets that make match play so engaging.

Good Golf Etiquette: How to Avoid This Entire Situation

As they say, an ounce of prevention is worth a pound of cure. While knowing the rules is important, playing a "clean" round where you don't even have to invoke them is far better. Here’s how to avoid hitting other golf balls on the green altogether.

Always Mark Your Ball

This is the golden rule of putting green etiquette. The moment all players in your group have reached the putting surface, everyone should immediately mark the position of their ball with a coin or a flat ball-marker. Once marked, you can pick up your golf ball to clean it. This simple act removes nearly all possibility of an accidental collision.

Determine the Order of Play

The general principle in golf is that the player whose ball is farthest from the hole plays next. On the green, this system keeps things orderly. A quick bit of communication like, "I think you're away, John," or, "Shall I go ahead and putt?" clarifies the sequence and ensures everyone is ready and paying attention. If it's your turn to putt, politely ask other players whose balls might be on your line, "Could you mark that for me, please?"

Know When to Putt Out

The only exception to marking is often for quick, short tap-ins. To maintain a good pace of play, if a player has a putt of a foot or less, the group will often let them go ahead and "tap it in" to finish the hole, even if it’s not technically their turn. This is fine, as long as everyone in the group is aware and agrees.

Final Thoughts

To recap, what happens when a golf ball hits another on the green comes down to your playing format. In stroke play, a putt that hits another ball on the green results in a two-stroke penalty for the putter. In match play, there is no penalty, and the opponent has the option to replace their ball or play it where it lies. The easiest way to deal with this rule is to avoid invoking it altogether by practicing good on-course etiquette, communicating with your partners, and always marking your ball.

Mastering the Rules of Golf is a big step toward playing with confidence, but it can feel like having to memorize a textbook before a big test. That's why Caddie AI is designed to be your on-demand rules expert. When you find yourself in a confusing situation like this and feel that knot of uncertainty, you can ask Caddie AI for a simple, clear explanation in seconds. We give you that instant support so the guesswork disappears, helping you make the right call, avoid penalties, and focus on playing your best golf.