As you probably know, the ATP has a precise rule to assure that players give their best effort during a match, and umpires can hand out lack of effort warnings, and penalties, as they want to protect the quality of their product and ensure fans get their money’s worth.
In the past, at the ATP World Tour level there were a handful of examples of players caught and fined: the most famous one is by Nikolay Davydenko in ATP St. Petersburg 2007.
Sometimes tanking has been related to match fixing as well, and the terms can occasionally be synonymous if the player is known for irregular betting patterns. You would be surprised to know that also Roger Federer was found guilty of the violation of this rule.
Two of the most famous tankers on ATP Main Tour are surely Bernard “The Tank Engine” Tomic and Fabio Fognini. Tomic, who holds the record for the fastest ATP Tour loss (Miami 2014 to Jarkko Nieminen in 28 minutes)has been booed for poor effort at ATP Master Series Miami 2013 and has been accused of tanking by John McEnroe at US Open 2012 against Andy Roddick.
Fognini, probably the biggest mystery on tour these days given his headcasery, became famous more for his shows on court (versus empire, opponent and even his own box) than for his rare talent. During ATP Master Series Cincinnati 2013 Radek Stepanek managed to break him for the match without touching the ball.
Nowadays it is pretty difficult to observe tanks on ATP World Tour because almost every match is televised and ATP players have sponsors that surely don’t like to watch those poor efforts. but on the ATP Challenger Tour it still happens, and it happens with no fines for players involved.
Gael Monfils during last Wimbledon tanked a few points (watch until 0:36) but then managed to fight until the end of the match.
During the last months we had clear examples of tanks on ATP Challenger Tour: Michal Przysiezny (that later revealed he didn’t like playing at high altitude) tanked 2nd round of Guadalajara Challenger a few weeks ago.
Did you see that 1st and 2nd served on mp down? If you enjoyed the video you better watch what Andreas Haider Maurer did less than one year ago: complete no effort and funny second serve 0-40 down in Poznan Challenger Quarterfinal.
Tanks in doubles happens more often than in singles because generally singles players tend to not care about doubles, and at Challenger level the prize money is pretty low so sometimes players decide to tank doubles to play qualifying of next tournament or just to arrive there earlier. The following happened this year at Maui Challenger: no fine for Michael Shabaz and Wayne Odesnik.
In what can be considered karma, that was the last match ever for Odesnik that a few weeks later has been banned for 15 years, for doping.
Personally I don’t have anything against tanks (most of them are even funny as you could watch) but I have to admit that if a rule exists it has to be applied and I dont think that spectators that payed a ticket to watch a good tennis show are happy to see tanks: can you imagine a football match where a team deliberately let the opponent score or don’t run to catch the ball?