It seems utterly absurd that professional, highly-trained and incredibly powerful tennis players would even contemplate serving underarm.
Why would anyone trade a 140-160mph first serve for an embarrassingly slow offering?
But that is exactly what two players have decided to do already at this year's US Open. It seems almost incomprehensible, but with a pair of players doing so in the first week of a tournament means it is now big news.
So why would top-level players even entertain the prospect of jeopardising their chances with a half-hearted slow serve?
Well, the two instances are very different: the first as a frustrated response to an injury; the second as a cheeky effort to get the crowd on side in the middle of a heavy defeat.
Wimbledon semi-finalist Jerzy Janowicz was showered with boos for serving underhand during his quick opening round exit, and the Pole blamed the situation entirely on an injury.
Hampered by a back issue sustained in the gym on Saturday, the normally temperamental world number 14 hobbled through a 6-4 6-4 6-2 loss to world number 247 Maximo Gonzalez of Argentina.
Janowicz had 53 unforced errors, threw his water bottle on the court, argued with the umpire and earned the wrath of the crowd at Flushing Meadows when he resorted to serving underhand in the fifth game of the third set.
"On my push, I wouldn't call it a serve, he hit two winners on my push, so I decided to try something else," Janowicz said of the decision to serve underhand.
Janowicz's normally powerful delivery was barely registering 100 miles per hour. He trudged around the court, making his feelings obvious, before he used the underhand delivery when the match was slipping away.
He said a request for pain killers in the third set was rejected since he had received a strong dose earlier on Tuesday.
"It was like being stabbed in the back by a knife," the 22-year-old said of his injury. "I felt bad in my lower back. For three days I haven't been able to practice, I could barely walk. I was in really good shape before this happened and that's why I'm fricking disappointed.
"I was just working hard in the gymnasium when it happened. Today before the match I had injections, strong pain killers. But I couldn't serve. I just couldn't serve."
The second case saw the typically eccentric Michael Llodra of France attempt to either rile or amuse his opponent, defending champion Andy Murray, in their first-round match at Flushing Meadows.
Llodra, serving to stay in the match, lit up the Arthur Ashe Court for the late-night fans with an impromptu under-arm serve that Murray retrieved, prompting an athletic dive-and-tumble get by the Frenchman, the point finished with a cheeky pop into empty space.
The final point was similar and they embraced, smiling, at the end – a nice counterpoint to a day of rain disruption and the sadly familiar schedule horrors that have plagued this tournament for years, but it was the cheeky underarm serve that was most notable.
Llodra's effort produced a very mixed response from tennis fans on social networks, but while Janowicz was booed, the Frenchman received a warm reception from supporters in the stadium.
— Andy Oliver (@Andy1ohhh) August 29, 2013
Llodra, ever the joker, played an underarm serve to Murray in the final game. The 'unpredictable' tag Murray gave him was very fitting. — David McDaid (@BBCDavidMcDaid) August 29, 2013
Llodra served underarm to Murray tonight; Berdych did it in Montreal (and Gulbis?), Janowicz another one here. #forgottenart
— kevin mitchell (@kevinmitchell50) August 29, 2013
With Tomas Berdych also producing a 'cheeky' underarm serve in Montreal, are we seeing the re-emergence of a long lost 'forgotten art' with players deliberately attempting to outfox their opponent and to catch them off guard at the back of the court?
Llodra's effort against Murray was certainly an attempt to catch out the reigning champion in New York, albeit that he did not go on to win the point.
But it remains a viable option for players in the same way that a drop shot can add an element of surprise to an otherwise prosaic 'baseline-slogger' approach that so many modern-day players employ and rarely err from.
Dustin 'dreddy' Brown produced some sparking serve-volley tennis at Wimbledon to delight the SW19 crowd, so is underarm serving something we will see more of at the top-level? Only time will tell, but the likes of Llodra definitely seem to believe it is just a legitimate tactic.
Is serving underarm disrespectful and unsporting? Is it entirely stupid and frustrating to watch? Or is it part of a forgotten art and just a strategic ploy? Post your comments below...