On the Green Rules — Marking, the Flagstick, and Ball Interference
What changed in 2019 and what stayed the same
The short answer: on the green you may mark and lift your ball, and you may putt with the flagstick in. Hitting another ball on the green normally means two penalty strokes.
A playing partner's ball blocks your line, so ask them to mark it. If your putt hits another ball on the green, take two penalty strokes and play from where your ball lies.
🎮 Practice green rules on Konkuk CC →The green has more rules packed into a small area than anywhere else on the course. Marking, flagstick positioning, ball interference, line of putt protection — all of it concentrated in the last 10 to 50 feet of every hole. The 2019 rules revision simplified a few of these significantly. Here's what actually matters.
Marking your ball — the right way
Before lifting your ball on the green, mark it. Place a coin or ball marker directly behind the ball — on the side away from the hole. Marking to the side or in front shifts your ball's starting position and can affect your line.
Lifting the ball without marking it first is a one-stroke penalty. If your marker is in another player's line of putt, they can ask you to move it — usually one or two club-head lengths to the side. When you're ready to putt, replace the marker exactly where it was. Forgetting to move it back and putting from the wrong spot costs a penalty.
The flagstick — the 2019 change that surprised everyone
Before 2019, if your ball hit the flagstick while putting from the green, you received a two-stroke penalty. Now it's completely legal to leave the flagstick in the hole and putt — even if the ball hits it and drops in, the hole counts.
The key change covers the flagstick when it is left in the hole. Some players find it helpful on long putts, since the flagstick can stop a ball from rolling past. Others prefer to pull it out of habit. Both are legal.
Practical guidance: the simplest approach is to leave the flagstick in the hole or have it fully removed before putting. Attendance scenarios — where someone holds the flagstick during your stroke — involve additional nuances in the rules, so when in doubt, remove it completely.
Ball hits another ball on the green
In stroke play (standard rounds), if your putt hits another ball at rest on the green, you get a two-stroke penalty — the penalty is yours as the player who made the stroke. The ball you hit (the stationary one) is replaced to its original position. Your ball (the one you putted) is played as it lies, wherever it stopped.
To avoid this, offer to mark your ball when it's on another player's putting line. The two-stroke penalty falls on whoever made the putt any time both balls were on the putting green before the stroke — regardless of whether anyone asked for a mark.
This two-stroke rule applies to any stroke played from the putting green that hits another ball at rest on the putting green — not just putts specifically. If you chip or play from off the green and happen to hit a ball on the green, there's no penalty.
Frequently Asked Questions
Can I putt with the flagstick in?
Yes. Since the 2019 revision, leaving the flagstick in while putting is allowed.
How do I mark and replace a ball?
Place a ball-marker immediately behind the ball, lift it, and replace it on the same spot.
What happens if my ball hits another ball on the green?
In stroke play it normally brings a two-stroke penalty, and the moved ball is replaced.
Related terms
💡 Key Takeaway
Always mark before lifting your ball on the green. It takes two seconds and prevents a one-stroke penalty.
Not sure about a golf term? Check the glossary.
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