SINCE THE DAYS when it was first played over 1,500 years ago, chess has garnered a wide range of enthusiasts, from King Edward I to Napoleon to former President Jimmy Carter. However, one thing is likely certain: None of those people reached checkmate while rocking goggles in a pool.
American chess master Etan Ilfeld created "diving chess" in 2012 as part of the annual Mind Sports Olympiad (the competition's 30th anniversary is later this month in London). Instead of facing another player in an environment where air is abundant, Ilfeld added a simple yet challenging twist.
Chess would be played on a weighted board at the bottom of a pool. During tournament play, the board is typically 3.2 to 5.6 feet underwater. There's no time limit. Wet suits and weights are barred from use.
Players can make a move only while underwater, and after making a move, a player can surface for breath, at which time their opponent must submerge to make their move. Coming up for breath without moving a piece results in a warning on the first offense. If you do it once more, you lose.
"Some chess players think that chess is already a sport, and others don't. And I was like, well, let's find a way to make it a sport while still focusing on the chess," Ilfeld told ESPN. "So that was really the inspiration, was trying to find some way to make it more athletic without diminishing the importance of the actual game."
• Watch diving chess -- along with slippery stairs, roofball, hacky sack and many other sports -- during the 10th anniversary edition of The Ocho, airing Thursday through Sunday.
Ilfeld had seen chess boxing, which has alternating rounds of chess and boxing. However, he wanted to create a physical form of chess that didn't depend on body size or other physical characteristics. He came up with diving chess.
The popularity of Ilfeld's idea has reached novices and grandmasters alike, coinciding with an ESPN Ocho broadcast Saturday, marking the second straight year the event has been included. (Last year's diving chess episode will also re-air this week.)
Grandmasters such as Americans Hans Niemann and Fabiano Caruana as well as India's Vidit Gujrathi have played matches. Lithuanian grandmaster Paulius Pultinevičius won the world championship in Poland in May.
Cuban American grandmaster Leinier Domínguez said it's like normal chess with an athletic edge. The World Chess Hall of Fame included diving chess in an exhibit titled: "Game Plan: The Strategy of Chess & Sports."
Self-described as "the internet's chess teacher," Levy Rozman highlighted it on his YouTube page. Rozman said in the video: "This is the strangest sport in the world."
Momentum for the sport ramped up in the past eight months, according to Ilfeld, and the growth has been organic. Diving chess matches have taken place in locations such as Cape Town, South Africa; St. Louis; and the Netherlands.
"It's really cool when you don't have to actually push to make something happen. The universe kind of wants you to come and create more of it," Ilfeld said.
Diving chess's benefits and obstacles are as simple as the rules. Holding one's breath underwater is already a physical challenge. Throw in chess strategies such as identifying forks and castling early, and the difficulty increases.
Breath control and comfort in the water are requirements. Though it depends on the pool, there is no set water temperature. Matches are usually held indoors, therefore pools can have temperatures on the cooler side, adding another variable to tackle. But, at the end of the day, "the outcome is still decided by the chessboard," Ilfeld said.
Being able to properly sink to the board is an underrated skill since humans tend to naturally float.
"When you're not going to get to the bottom of the pool, you need to kind of gradually either exhale or swim to the bottom," Ilfeld said. "And you're going to do a sort of combination of the two because if you just exhale and go to the [bottom] too quickly, then you'll run out of breath really quickly."
The routine of going underwater and staying close to the board takes a couple of hours to learn, Ilfeld added. Domínguez adjusted so well that in one match he bumped into the bottom of the pool after dropping too fast.
Ilfeld admits the chessboard's design is something that they are still perfecting. Ilfeld has been sourcing and creating underwater chess sets that can be submerged for up to eight hours.
The magnetized board has a dense plastic construction that allows it to naturally sink and stay in place without added weights. It weighs around four pounds, and the pieces collectively weigh around two pounds and are also magnetized. Attaching magnets to a regular chess set wouldn't work because the players' movements in the water could still send the pieces flying.
In the latest ESPN Ocho event, former diving chess world champion Michał Mazurkiewicz and Ilfeld played in an underwater cage in South Africa as sharks swam around them.
For Ilfeld, it's another example of his willingness to travel anywhere to create content to grow the game.
"It's just been awesome, so now it's really [about] kind of keeping the momentum," Ilfeld said.
One checkmate at a time.