Explaining the Through Line in Golf

The "through line" in golf is the extension of a golfer's putting line several feet beyond the hole. Or, to express it two other ways, a) the through line is the putt you'll have coming back to the hole if you miss long with your initial putt; b) the through line is the line on which the ball will keep rolling beyond the hole if you miss the cup with your first putting attempt.

The "putting line" is the path on which your putted ball travels toward the hole; the "through line" is the continuation of that path a few feet past the hole.

Note that the term is sometimes spelled "through-line," "thru-line" or "thru line."

Who Cares About Through Lines?

Some golfers take through lines very seriously. Recreational golfers typically don't; pro golfers typically do. But as a matter of courtesy, as a matter of golf etiquette, you should be aware of other golfers' through lines. You don't want to encounter that one guy who is dead serious about his through line and will make a scene if you happen to step on his.

Do you need to care about your own through line? Jack Nicklaus once said he never cared about his own through line, stating that any golfer already thinking about his through line is already thinking about missing the putt. Forget about your own through line and instead visualize your initial putt dropping into the cup.

But it's a simple matter of good golf etiquette to care about the through lines of other golfers in your group. You would never intend to step on another player's putting line, and if you did you'd feel bad about it. It's easy enough to be aware of through lines, just as it is to be aware of putting lines.

How Far Does a Through Line Extend?

So if it's good golf etiquette to be aware of other golfers' through lines, just how much leeway past the hole should you give them? Should you avoid stepping on that through line one foot past the cup, three feet ... 10 feet?

A golfer who snipes at another for walking across his through line eight feet beyond the cup when the initial putt is only 12 feet is a golfer who has bigger issues than worrying about through-line etiquette.

But you should take that initial putt into account. A 6-foot, straight, uphill putt obviously should result in a much shorter comebacker (if the golfer misses long) than a fast, downhill, breaking 25-footer.

But, generally speaking, granting other golfers three to four feet for a through line, and stepping around the hole accordingly, is sufficient for most putts.