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Impact Lab Golf
Putter Lab · 2 Hours

Four Readings Decide Every Putter We Recommend

Face angle at separation, launch off the face, skid distance before true roll, and the width of your stroke arc. Everything else — toe hang, lie, loft, length, head shape — falls out of those four numbers.

Reading One

Face Angle at the Moment the Ball Leaves

Start line on a putt is dominated by face angle to a degree that surprises most players. Depending on whose research you read, somewhere between eighty and ninety-two per cent of the initial direction comes from where the face is pointing, with path contributing the remainder. Path gets most of the attention in practice, and it is the smaller term.

Measuring face angle properly is harder than it sounds, because what matters is the angle at the instant the ball separates from the face, not at some approximation of impact. Contact lasts under a millisecond and the face is still rotating throughout it. Our lane camera runs at a thousand frames a second and is triggered off the strike so that the separation frame is captured reliably.

That reading tells us whether the face is consistently open, consistently closed, or simply variable. Those three findings lead to entirely different recommendations, and a fitting that guesses between them is a coin toss.

Roll Lane Equipment

  • Lane length14 ft
  • Surface speedStimp 10.5, adjustable
  • Face camera1,000 fps, strike triggered
  • Roll cameraSkid to true roll
  • Arc traceOverhead path capture
  • Head inventory60+ across five hosel styles

Toe Hang Classes on the Rack

  • Face balancedMinimal rotation
  • Quarter toe hangSlight rotation
  • Half toe hangModerate rotation
  • Three-quarterSubstantial rotation
  • Full toe hangMaximum rotation

Half toe hang fits a wider band of players than any other class once arc is actually measured, and face balanced is the most over-prescribed.

Reading Two

Stroke Arc Width, Then Toe Hang

Every putting stroke is an arc. The head is attached to a shaft, the shaft is attached to a body that turns, and unless the stroke is extremely short the head will travel inside the target line going back and again coming through. The question is not whether you have an arc but how wide it is.

The overhead trace measures that width in inches over a ten-foot stroke. A narrow arc with little face rotation wants a putter whose balance resists rotation — toward the face-balanced end. A wide arc with substantial rotation wants a head that rotates willingly, which means toe hang.

Match those correctly and the face returns to square without conscious manipulation. Mismatch them and the player spends every round making a small compensating adjustment, which works on Tuesday and does not work on Sunday.

More on toe hang
Reading Three

Launch, Skid and the Point True Roll Begins

A putted ball does not roll immediately. It launches slightly upward, skids across the grass while backspin bleeds off, and only then begins to roll forward properly. The distance covered in that skid is measurable and it matters, because a ball that is skidding is being pushed around by every imperfection in the surface it crosses.

Shorter skid means the ball starts obeying the line you gave it sooner. On a fast green with a subtle break, the difference between six inches of skid and eighteen is the difference between a putt that holds its line and one that wanders.

Skid distance is governed by delivered loft, which is a combination of the putter's static loft and how much shaft lean you present. This is why static loft cannot be chosen from a chart: a player with six degrees of forward lean and a four-degree putter is delivering negative loft, driving the ball into the ground and producing a long skid. The same putter in the hands of someone with a neutral shaft position performs perfectly well.

We measure your delivered loft, then choose static loft to land the launch in the right window. It is one of the few changes in golf where the improvement is visible to the naked eye on the very next putt.

Roll Targets We Work To

  • Launch angle0.8 to 2.0°
  • Skid distance, 10 ft puttUnder 12 in
  • Delivered loft1 to 3°
  • Static loft range on rack1 to 6°

Measured at Stimp 10.5. Slower surfaces tolerate a little more launch than faster ones.

Reading Four

Lie Angle and Length, Which Set Everything Else Up

Lie

If the toe or the heel is off the ground at address, the effective face aim changes before you have moved. A putter sitting toe-up aims left of where it looks for a right-handed player, and the amount is large enough to miss from six feet.

Most putters are sold at seventy or seventy-one degrees and most players are not. We measure the lie you present in your actual posture and bend the head to match, which is bench work we do on site.

Length

Length determines where your eyes sit relative to the ball, and eye position determines whether the line you see is the line that exists. Eyes inside the ball tend to produce a push; eyes outside tend to produce a pull.

Stock length is thirty-four inches and it is stock for manufacturing reasons rather than fitting ones. A large share of the players who come through the lab end up between thirty-two and a half and thirty-three and a half.

The Two Hours

How a Putter Lab Session Runs

  1. Baseline on Your Own Putter

    Twenty putts at ten feet with the putter you play, capturing all four readings. Nothing is changed and nothing is judged yet.

  2. Address Position and Lie

    We check how the putter sits in your posture and how your eyes fall relative to the ball. Lie and length are adjusted before anything else, because they change the other three readings.

  3. Arc Trace

    The overhead capture measures arc width over a full stroke. This produces the toe hang bracket the rest of the session works inside.

  4. Head Comparison Within the Bracket

    Three or four heads across the correct toe hang class, differing in shape, weight and alignment treatment. Twenty putts each, compared on face angle consistency rather than on holed count.

  5. Loft to the Roll

    Static loft chosen against your measured shaft lean to bring launch and skid into the target window. Bent on site where the head allows.

  6. Grip Shape and Weight

    Grip geometry changes hand pressure and therefore face rotation. Tested last because it is the variable most easily changed afterwards.

  7. Confirmation and Printout

    A final twenty putts on the chosen configuration, and a printed record of every reading against the baseline.

Reading Further

Bench Journal Entries on Putting

Toe Hang and Face Rotation

Why the balance point of a head should be derived from measured rotation rather than chosen by feel.

Read it

Putter Lie Angle at Address

How much a putter sitting two degrees off the ground moves your start line before the stroke begins.

Read it

Arc Shape and Path Consistency

Straight-back-straight-through describes a very short putt, not a stroke type. What the trace actually shows.

Read it

Two Hours in the Roll Lane

Bring the putter you use now and, if you have them, the two you gave up on. Understanding why they failed is frequently the fastest route to the one that will not.