With key male swimmers of recent editions of FINA World Championships missing out on Budapest, a whole new lane of opportunities has opened for future champions.
· The most successful male swimmer in Kazan in 2015 in men's events was Florent Manaudou (FRA), who took three gold medals. He claimed gold in men's 4 x 100m freestyle, men's 50m butterfly and men's 50m freestyle.
· Following the Rio 2016 Olympic Games the Frenchman decided to give competitive swimming a break and revert to a sports passion from his childhood, handball, a sport in which France has been among the world's leading nations for decades.
· Manaudou collected two silver medals in Rio, in men's 4 x 100m freestyle and men's 50m freestyle.
· The most successful male swimmer at the 2011 World Championships in Shanghai as well as the 2013 World Championships in Barcelona was Ryan Lochte (USA), who is currently serving a ban imposed on him after 2016 Rio Olympic Games.
· Lochte won six medals (G5-S0-B1) in 2011 and added four more (G3-S1-B0) in 2013.
· In his career, Lochte has won 18 gold medals at the World Championships, second to the 26 by Michael Phelps (USA) and seven more than the next most prolific competitor, male or female either.
· Lochte's 27 career medals (G18-S5-B4) are second to Phelps's 33 and eight more than next most prolific swimmers. Grant Hackett (AUS) and Natalie Coughlin (USA) have both claimed 19.
· Phelps was the most successful swimmer in men's events at four different World Championships: Barcelona in 2003, Montreal in 2005, Melbourne in 2007 and Rome in 2009.
· Phelps retired after emerging as the most successful athlete in all sports at the Games in Rio, collecting five gold medals and a silver. In his last hurrah, Phelps raised his career total of Olympic gold medals to 23, which is 14 more than of the next most successful athletes in Olympic history.
· With these men missing in action, the most successful male swimmer present in Budapest is Sun Yang (CHN), who has seven world titles to his name (G7-S2-B3) so far.
· Sun, a specialist in distance swimming, will take part in at least two events in Budapest and could be looking to equal the 10 career world championships gold medals by both Hackett and Aaron Peirsol (10).
· The two men on 10 are only topped by Phelps on 26, Lochte on 18 and Ian Thorpe (AUS) on 11.
· No Asian swimmer has ever emerged as the dominant male swimmer at a single World Championships edition. So far it has been achieved solely by swimmers representing the United States, Russia, Australia and France.
· Katie Ledecky (USA) is hoping to win the 200m, 400m, 800m and 1500m freestyle events for the second World Championships in a row.
· In 2013 Ledecky won three out of the four longest freestyle events, with the exception of 200m which was won by Missy Franklin (USA).
· Across all events, Ledecky has won nine world titles, just two shy from women's record held by Franklin (11).
· Ledecky won 14 of the 15 events she took part in at the Olympic Games and World Championships so far. She only failed to win the 4x100m freestyle relay at Rio 2016 Olympic Games where the US team finished second behind Australia.
· Sarah Sjöström (SWE, 100m butterfly) and Katinka Hosszú (HUN, 400m individual medley) are vying to become the first women with four world titles in an individual event.
· Hosszú won the individual medley double at the last two World Championships editions. She could become the first woman to do so at three editions in a row.
· In total, Hosszú has claimed nine World Championship medals (G5-S0-B4). She is aiming at becoming the second swimmer from Hungary to reach double figures, after László Cseh (HUN) who has claimed 12 medals coming into this year's edition (G2-S5-B5).
· Sarah Sjöström has claimed eight medals at the World Championships (G4-S3-B1) and is hoping to become the most decorated Swede, male or female, in the history of the tournament. She currently shares the record of eight medals with Therese Alshammar (SWE, G2-S5-B1).
· Ledecky (400m, 800m and 1500m freestyle), Sjöström (100m butterfly) and Hosszú (200m and 400m individual medley) can all win a specific event at three successive World Championships editions. Prior to this tournament no woman has ever achieved it in an individual event.
· Federica Pellegrini (ITA) has claimed six medals in women's 200m freestyle (G2-S3-B1). She can become the first swimmer, male or female, to bag seven medals in an individual event at the World Championships. She now shares the record of six with Ryan Lochte (USA, men's 200m individual medley, G4-S1-B1).
· Canada has claimed 18 medals in women's events at the World Championships (G0-S4-B14), but is still short of their first women's world title.