The 28th Africa Cup of Nations begins Saturday, co-hosted by Equatorial Guinea and Gabon. With the help of ESPN's Soccer Power Index, here is a look at each team's chances of advancing to the knockout stage, along with the surprising list of teams that were eliminated in qualifying:

•  A dominant storyline entering the tournament is the countries that didn't make it. Of the six African teams that participated in the 2010 World Cup, four failed to qualify for the Cup of Nations: Algeria, Cameroon, Nigeria and South Africa, who have combined to win eight of the 27 previous championships.

•  Perhaps the most notable country missing is Egypt, which has won the last three titles and a record seven overall. Egypt (26th), Cameroon (40th) and Nigeria (41st) are three of SPI's five highest-ranked teams in Africa.

Group A

•  Group A is the weakest and also most balanced group according to SPI. Senegal is the group favorite, with a 69.7 percent chance to advance, followed by Libya (52.6 percent), Zambia (48.6 percent) and Equatorial Guinea (29.1 parent), which is making its tournament debut. The other three countries have all finished runner-up but never won the title.

•  Zambia and Senegal have the most Cup of Nations appearances without ever winning the championship, with 14 and 11, respectively.

Group B

•  Group B is the strongest group at the tournament, with three of the top seven teams in the competition. Ranked 10th in the world by SPI, Ivory Coast is favored to win the tournament and a 92.3 percent favorite to advance to the quarterfinals. Angola (46.7 percent) and Burkina Faso (45.0 percent) are expected to battle for the group runner-up spot, with Sudan (16.0 percent) a long shot to advance.

•  Ivory Coast's sole Cup of Nations title came in 1992, when the Elephants defeated Ghana on penalty kicks in the final by an astonishing 11-10 score.

•  Sudan is the only other country in the group with a championship, winning as host nation in 1970.

Group C

•  With an 89.2 percent chance to advance, Gabon is a significant favorite in Group C, largely because of the home-field advantage the Panthers will enjoy. Without that edge, Tunisia (62.0 percent) and Morocco (44.7 pct) would join Gabon in a very even three-horse race to reach the quarterfinals.

•  Rated 139th in the world by SPI, debutant Niger is the tournament's worst team, with merely a 4.2 percent hope of advancing. Tunisia and Morocco have each won one title previously, with Tunisia defeating Morocco 2-1 at home in the 2004 final.

Group D

•  2010 runner-up Ghana has won four titles, most of any team at the tournament, but the Black Stars' last championship was in 1982. At 86.3 percent to advance, Ghana is a heavy favorite in Group D, trailed by Mali (49.2 percent), Guinea (38.1 percent) and debutant Botswana (26.4).

•  Ghana's eight final appearances are tied with Egypt for most all time, while Mali and Guinea have each made a single final.