Germany's Matti Schmid utilized his broom-handle putter to reside his shot arsenic he faced different important tap-in en way to 2nd spot astatine nan Charles Schwab Challenge connected Sunday - his champion PGA Tour finish.
Briefly, nan tv cameras showed nan apical extremity of his club. A clenched near manus had its thumb resting connected apical of nan grip. His bluish patterned garment creased astir nan knuckle of his thumb.
The image begged immoderate questions: was that knuckle besides successful interaction pinch his chest? If so, was it wedged against his sternum? Had he recovered a fixed anchor point? Was he breaking nan rules? Or was it OK?
BBC Sport has contacted Schmid's representatives, but nan very truth his method could beryllium questioned - pinch nary definitive reply - intends a superb putting show could autumn nether an unwelcome spotlight.
Rule 10.1 of nan Rules of Golf states: "When making a stroke, a subordinate must not anchor nan club" by "doing it 'directly', by holding nan nine aliases a 'gripping hand' against immoderate portion of nan body".
There was surely nary daylight betwixt Schmid's near thumb and his shirt, and erstwhile I showed a screengrab of nan image to a starring referee he acknowledged it was a "bad look".
But he besides pointed retired that nan rules state: "If nan player's club, gripping manus aliases forearm simply touches their assemblage aliases clothing during nan stroke, without being held against nan body, location is nary breach of this rule."
So we - arsenic observers - do not cognize whether Schmid's putt was ineligible aliases not.
Despite legislation coming into effect almost a decade ago, nan rumor of 'anchoring' continues to beryllium 1 of nan murkiest successful nan game.
If anything, it feels arsenic though it is becoming ever much pertinent.
Schmid topped nan putting stats astatine Colonial arsenic he vanished 2nd to Ben Griffin. After gaining much than 8 strokes connected nan section pinch his prowess connected nan greens, that runner-up decorativeness propelled nan two-time erstwhile European Amateur champion to 55th successful nan PGA Tour's FedEx Cup standings.
None of this is to opportunity nan 27-year-old's action collapsed immoderate rules. There whitethorn beryllium capable lateral activity successful his changeable to propose he is not stabilising to a fixed point.
But nan broader taxable remains 1 of nan hottest successful master locker rooms.
"He's astir apt OK," nan referee I said to added. "He's astir apt conscionable rubbing nan garment material, but by what he is trying to execute he's going to beryllium arsenic adjacent arsenic imaginable to his chest, and truthful subordinate integrity comes into it."
Another official, who referees connected nan DP World Tour, said connected information of anonymity: "It is ace difficult to enforce.
"We person spoken to a mates of players who we felt were getting adjacent to breaching nan norm and they really person gone backmost to shorter putters, which is good.
"But yet you person to spell pinch nan integrity of nan players. How do you enforce it? It is your connection against theirs. You're successful nary man's land."
The norm was introduced successful 2016 aft a spate of fields were won by golfers utilizing extended putter shafts.
Keegan Bradley anchored successful his midriff to win nan 2011 US PGA, arsenic did Ernie Els for his Open triumph nan pursuing year. There were broom-handle awesome wins for Webb Simpson successful nan 2012 US Open and Adam Scott a twelvemonth later at nan Masters. The Aussie continues to usage nan agelong putter, but pinch daylight betwixt his changeable and his body.
Protecting nan "fundamental characteristics of nan putting stroke" was nan logic for banning anchoring 9 years ago.
It is OK for an extended shaft to beryllium clamped against a forearm (as US Open champion Bryson DeChambeau does) because that moves to make nan hit.
But location are those successful nan crippled who consciousness moreover this method makes putting "too easy".
And location are plentifulness much exponents who proceed to shun normal and spell pinch longer implements. Along pinch Schmid, nan likes of Akshay Bhatia, Si Woo Kim and Lucas Glover usage these perchance contentious clubs to awesome effect.
Bernhard Langer and Scott McCarron person agelong endured their techniques being questioned connected nan Seniors tour, and Spaniard Eugenio Chacarra's Indian Open triumph connected nan DP World Tour past March drew focus.
Langer and McCarron person vehemently denied breaching nan rules.
Back successful 2017, Langer said: "I personally don't understand it because I'm a man of integrity, and nan past point I want to do is break rules and beryllium known arsenic cheating.
"I cognize erstwhile I'm anchoring and erstwhile I'm not anchoring because I power my hand. It goes sideways, you tin spot it.
"So erstwhile my knuckle is distant from nan body, I'm not anchoring aliases rubbing immoderate portion of my assemblage and I cognize I'm wrong nan rules."
The problem is that successful galore cases it is not evident to nan naked oculus and is intolerable to enforce either way.
It intends an rumor arsenic basal arsenic nan putting changeable is shrouded successful much grey areas than a flotilla of battleships, which is highly unsatisfactory and not adjacent connected nan likes of Schmid erstwhile they predominate truthful brilliantly connected nan greens.
DP World Tour victor Eddie Pepperell believes nan solution is "quite simple".
"Insist connected nan putter being nan shortest nine successful nan bag," he told nan Chipping Forecast podcast.
Some referees agree.
"Easy solution is conscionable limit nan maximum magnitude of nan putter and beryllium done pinch it," said 1 official.
Another said: "The powers that beryllium should beryllium looking astatine it. If location is simply a rule, we should beryllium capable to enforce it."