LONDON -- Handoff day is here. The Olympics' second Saturday is about transition.
Michael Phelps concludes his Olympic career on the final night of swimming, taking his customary butterfly leg in the 4x100-meter medley relay as part of four finals at the Olympic Aquatics Centre. Across Olympic Park, track and field gets going in earnest. On the same day of Phelps' final strokes, Usain Bolt will take his first strides of these Games in the opening round of the 100 meters. Later tonight, the world's fastest woman will be crowned. Will a Jamaican continue to hold that title (either defending champion Shelly-Ann Fraser-Pryce or world silver medalist Veronica Campbell-Brown), or will Carmelita Jeter become the first American to sprint to victory since Marion Jones in 2000 Gail Devers in 1996?
With two British superstars going for gold, Olympic Stadium will be at its loudest since Paul McCartney brought the opening ceremonies to a close July 27. Jessica Ennis, whose face is all over BBC commercials, countryside billboards and grass-field cutouts, takes a lead into the final three events of the heptathlon. Mo Farah goes the first half of a potential distance double in the 10,000 meters. And in the most anticipated women's tennis gold-medal match ever, Serena Williams faces Maria Sharapova in a rematch of their 2004 Wimbledon final. Medals will also be awarded today in badminton, track cycling, fencing, rowing, shooting, trampoline, triathlon and weightlifting.
• The U.S. has never lost the men's 4x100 medley relay (3:27 p.m.), the only other winner being Australia during the boycotted 1980 Moscow Games. The U.S. team is loaded again in this event with three individual Olympic champions on the projected four-man final lineup. It's Matt Grevers (100 backstroke gold) to Brendan Hansen (100 breaststroke bronze) to Phelps (100 butterfly gold) to Nathan Adrian (100 freestyle gold). The U.S. is SI's pick to win, followed by Australia and Germany. If that holds, Phelps finishes his career with 22 Olympic medals overall (18 gold, two silver, two bronze) and six medals (four gold, two silver) in London, which would be the most by any athlete at these Games.
The women's medley relay (3:07 p.m.) could be closer. Australia has won the last two titles, but this year's U.S. lineup is faster on paper. Let's break down the projected four legs based on their individual race times.
Backstroke: Missy Franklin (58.33) vs. Emily Seebohm (58.68)
Breaststroke: Rebecca Soni (1:05.55) vs. Leisel Jones (1:06.95)
Butterfly: Dana Vollmer (55.98) vs. Alicia Coutts (56.94)
Freestyle: Jessica Hardy (54.02) vs. Melanie Schlanger (53.47)
Total: U.S. (3:53.88) beats Australia (3:56.04)
With a U.S. win, Franklin, 17, will finish her first Olympics with four golds and one bronze, becoming the first woman to win four golds at one Olympics since Amy Van Dyken in 1996.
The world's fastest female swimmer will be crowned in the 50 free (2:30 p.m.). The Netherlands' Ranomi Kromowidjojo, the 100-meter gold medalist, was the fastest qualifier into the final by nearly three tenths (significant in a 50). Francesca Halsall is Great Britain's last hope to win its first swimming gold, and defending champion Britta Steffen of Germany is also in the medal picture.
The men's 1,500 free (2:36 p.m.) takes its customary spot as the last individual swimming event of the Olympics. This is Australia's Super Bowl, but for the first time since 1988, there are no Aussies in this final. The favorite hails from the country that has passed Australia as the second best swimming nation in the world -- China. Sun Yang goes for his fourth medal of the Olympics in his best event, the one he holds the world title and world record in. Defending champion Ous Mellouli of Tunisia qualified second behind Sun into the final.
• In track and field, the women's 100 meters (4:55 p.m.) is the capper of five finals. Carmelita Jeter, at 31 and making her Olympic debut, has been the most consistent performer since the Beijing Games. She's the reigning world champion. Only Florence Griffith-Joyner has run faster than her (though Jeter's two best times came three years ago). Defending Olympic champion Shelly-Ann Fraser-Pryce reasserted herself with the world's fastest time this year at the Jamaican trials and is SI's gold pick. The other Americans (Tianna Madison, Allyson Felix) and Jamaicans (Veronica Campbell-Brown, Kerron Stewart) are also in the medal picture, as is Trinidad and Tobago's Kelly-Ann Baptiste.
Somalia-born and Oregon-trained Brit Mo Farah will step up to the 10,000-meter start line (4:15) to deafening noise as the host nation's biggest male track and field star. Farah is the reigning world silver medalist and will be joined by American record-holder Galen Rupp in trying to break the Ethiopian grip on this event (four straight golds). Two-time defending Olympic champion and world-record holder Kenenisa Bekele is back for his third Olympics at age 30. Farah is SI's pick to win over Bekele.
Britain's best female gold-medal hope at Olympic Stadium is heptathlete Jessica Ennis, who owns a 184-point lead after four of seven events. The final three events are the long jump (5:05 a.m.), javelin (6:40 a.m.) and the 800 meters (3:35 p.m.). All of Ennis' primary competition are well back: top American Hyleas Fountain (fifth), 2011 world champion Tatyana Chernova (ninth) and 2008 Olympic champion Nataliya Dobrynska (10th).
Americans could medal in both the women's discus (2:30 p.m.), where Stephanie Brown Trafton is the defending Olympic champion, and the men's long jump (2:55 p.m.), which features University of Texas wide receiver Marquise Goodwin.
Usain Bolt, Yohan Blake and the rest of the world's fastest men will also go for a stroll in the first round of the 100 meters (7:30 a.m.), getting loose for Sunday's semifinals and finals.
• Maria Sharapova and Serena Williams return to the scene of perhaps the most memorable tennis match of this century for the women's final at Wimbledon's Centre Court. The winner of this match (following a 12 p.m. mixed doubles quarterfinal) will complete the career Golden Slam. Bob and Mike Bryan also go for a career Golden Slam against France's Jo-Wilfried Tsonga and Michael Llodra in the third match on Centre Court. Victoria Azarenka faces Maria Kirilenko and France's team of Julian Benneteau and Richard Gasquet faces Spain's David Ferrer and Feliciano Lopez in the respective bronze-medal matches.
• The tainted women's doubles badminton competition finishes up with bronze- and gold-medal matches (5:30 a.m., 10:45 a.m.) between a Russian and Canadian pair and a Chinese and Japanese pair, respectively. Women's singles medals will also be handed out.
• The U.S. men's basketball team, fresh off an 83-point dismantling of Nigeria on Thursday, will likely be tested a little more by Lithuania (9:30 a.m.) in its next-to-last group game. Lithuania nearly beat the 2000 Olympic team after Sarunas Jasikevicius' potential game-winning three-pointer missed the mark at the buzzer. Jasikevicius, the former Maryland and Indiana Pacers guard, is on this Lithuanian team along with the No. 5 pick in the 2011 NBA Draft, Jonas Valanciunas of the Raptors. The U.S. has already clinched a place in the quarterfinals.
• The round of 16 concludes in beach volleyball, where two more U.S. pairs are in action after Phil Dalhausser and Todd Rogers were eliminated Friday. Two-time defending Olympic champions Misty May-Treanor and Kerri Walsh Jennings, the third seed, face the Netherlands' ninth-seeded Marleen van Iersel and Sanne Keizer (4 p.m.). On the men's side, Jake Gibb and Sean Rosenthal get Russians Konstantin Semenov and Sergey Prokopyev (5 p.m.).
• In track cycling, the Great Britain women's team pursuit, which broke their own world record in qualifying, is a heavy favorite to win gold at the velodrome (12:42). The U.S. trio, not originally expected to medal, surprised by qualifying in second place.
• SI's picks to medal in the women's fencing team épée are China, Romania and Russia. The Americans are also among the field of eight.
• The men's soccer quarterfinals are Japan-Egypt (7 a.m.), Mexico-Senegal (9:30 a.m.), Brazil-Honduras (12 p.m.) and Great Britain-South Korea (2:30 p.m.). With wins, Brazil and Great Britain would play in the semifinals Tuesday.
• The rowing competition concludes with four finals -- women's single sculls (4:30 a.m.), men's and women's lightweight double sculls (4:40 a.m., 5 a.m.) and men's fours (5:30 a.m.).
•U.S. shooter Kim Rhode, the first American to medal in five straight Olympics with a skeet gold earlier in these Games, is in the field but not expected to medal in the trap (10 a.m.). Medals will also be awarded in the women's 50-meter rifle, 3 positions (7:45 a.m.).
• An American has never medaled in trampoline. Savannah Vinsant is the U.S. hope, but China and Canada field the best here (10:26).
• Triathlon gets started with the women's competition (4 a.m.) at Hyde Park. The U.S. qualified the maximum of three women -- Gwen Jorgensen, Laura Bennett and Sarah Groff -- in the field of 56.
• The medal-contending U.S. men's volleyball (versus Russia, 11:45 a.m.) and water polo (versus Serbia, 2:40 p.m.) teams look to stay perfect in their fourth of five preliminary games.
• Medals will be awarded in men's weightlifting's 94-kilogram division, where SI's pick to win is Kazakh Ilya Ilyin. No Americans are in the field.
"I'm a one-trick pony and he's the king," -- Serbian Milorad Cavic on Michael Phelps after their rematch in the 100-meter butterfly. Cavic led at the turn, but Phelps came back from seventh to win. Cavic got fourth.
1:20.48: The time it took Somalia flag bearer Zamzam Mohamed Farah to run one lap around the Olympic Stadium track, almost 30 seconds behind the winner of her 400-meter heat.
4 hours, 26 minutes: The length of Roger Federer's 3-6, 7-6 (5), 19-17 semifinal win over Juan Martin del Potro, the longest three-set men's match of the Open era.
£2: How much the John Lewis store in Westfield is charging people to look out its window to view Olympic Park.
1. African women swim in uncharted waters, By Andy Bull, The Guardian. A trio from Lesotho, Niger and Togo broke barriers in the pool.
2. Olympic Racewalking Is More Than Just A Stroll, by Ken Belson, The New York Times. An event mocked by many is serious business in some parts of the world.
3. If They Were Playing Olympic Golf in London. by John Paul Newport, The Wall Street Journal. Which golfers would be a part of the Olympics if it debuted in 2012 rather than 2016.