What happens if I use green-reading materials and get disqualified?

Yes, you can be disqualified. A first breach of the green-reading limits under Rule 4.3a costs you the general penalty — two strokes in stroke play or loss of hole in match play. A second breach for the same type of offense means disqualification.

What counts as a breach

Rule 4.3a says you can't use equipment that artificially eliminates the need for skill or judgment essential to golf. The clarification 4.3a/1 puts hard limits on green-reading materials: printed maps can't be larger than 4.25 x 7 inches (the size of a scorecard), and the scale can't show more detail than 3/8 inch to 5 yards. Any electronic or digital material has to meet the same size and scale limits. If your book or app exceeds those, you're in breach the moment you use it to read a putt.

How the penalty escalates

The first time you break Rule 4.3a during a round, you get the general penalty — two strokes in stroke play, loss of hole in match play. If you do it again for the same kind of breach (like checking an oversized green map on the 3rd green and again on the 9th), that second breach means disqualification. The penalties don't have to be on the same hole; they just have to be the same type of equipment violation during the same round.

When the committee bans everything

A committee can adopt Model Local Rule G-12, which modifies Rule 4.3a to prohibit ALL green-reading materials for strokes from the putting green. No books, no apps, no printed notes — nothing. If that local rule is in effect and you use any material to read your line on the green, it's a breach of Rule 4.3a right away. Same penalty progression: general penalty first time, DQ the second time.

Exceptions that change the answer

• The committee adopts Model Local Rule G-12 → All green-reading materials are banned for putts — even ones that would normally meet the size and scale limits. Using any material to read a green becomes a breach.
• You use a conforming green-reading book within the size and scale limits → That's allowed. You can consult it for putts without penalty, as long as it's 4.25 x 7 inches max and the scale doesn't exceed 3/8 inch to 5 yards.

Frequently asked questions

What if I accidentally look at an oversized green map someone else is holding?

Looking isn't a breach — you have to use the information to help your play. But if you deliberately check someone else's non-conforming book to read your putt, that's a breach of Rule 4.3a and the penalty progression applies.

Does the disqualification happen immediately on the second breach?

Yes. The moment you commit a second breach of the same type under Rule 4.3a in the same round, you're disqualified. You don't finish the hole or the round — you're done.

Can I use a yardage book with green contours for approach shots?

Yes. The size and scale limits in clarification 4.3a/1 only apply to strokes from the putting green. You can use detailed green maps for approach shots, chip shots, or any stroke not made from the putting surface.

What if I don't know the committee adopted Model Local Rule G-12?

Not knowing doesn't excuse the breach. It's your responsibility to check the local rules before you tee off. If G-12 is in effect and you use any green-reading material on the putting green, you're in breach regardless of whether you knew about the local rule.