The high school state basketball tournament begins this week with a record 224 first-round games Friday and Saturday, each played on the home court of the higher-seeded team.

Here is a primer on the tournament, first played in 1922, with news about a record six McDonald’s All-Americans, an old Atlanta school making its first appearance in 34 years and new venues for the state championship games.

What's new: There are seven classifications this year, up from six, and there will be 16 state champions crowned March 8-11. As recently as 2012, there were only five classes and 10 champions. For the first time, more than half of the GHSA's membership makes the playoffs.

The favorites: The No. 1-ranked boys teams are McEachern* (AAAAAAA), South Paulding* (AAAAAA), Buford* (AAAAA), Upson-Lee* (AAAA), Westside-Macon* (AAA), South Atlanta (AA), Greenforest Christian (A private) and Calhoun County (A public). The No. 1 girls teams are Norcross (AAAAAAA), Northview* (AAAAAA), Griffin* (AAAAA), Cross Creek* (AAAA), Johnson-Savannah* (AAA), Laney (AA), St. Francis (A private) and Pelham (A public). Those with asterisks have never won state titles in basketball. McEachern's girls can become the first to win the highest classification four straight times since Lowndes (1977-80).

Best first-round matchups: Class AAA has a couple of girls games between ranked teams - No. 9 Hart County at No. 10 Calhoun, and No. 5 Ringgold and No. 6 Franklin County. No boys game matches Top 10 opponents, as the expanded playoffs dilute the matchups, but No. 10 Collins Hill at frequently ranked Grayson, a Gwinnett rival, is probably the most intriguing.

Top boys players: Three McDonald's All-Americans have led their teams to the state tournament. They are Pebblebrook guard Collin Sexton (signed with Alabama), Jonesboro guard M.J. Walker (uncommitted) and Pace Academy forward Wendell Carter (Duke). Also watch for Auburn signees Chuma Okeke of Westlake and Davion Mitchell of Liberty County, whose teams are defending champions, and Norcross forward Rayshaun Hammonds, who has signed with Georgia.

Top girls players: The tournament also has three McDonald's All-America girls. They are center Kasiyahna Kushkituah (Tennessee) and wing Maya Dodson (Stanford) both of St. Francis, and Wesleyan guard Mikayla Coombs (UConn). The three play in the Class A private-school division as does Holy Innocents' poing guard Khayla Pointer (LSU).  Archer forward Autumn Newby (Vanderbilt) and McEachern guard Que Morrison (Georgia) Norcross guard Taylor Mason (Miami) and Brookwood forward N'ea Jones (Texas A&M) are top-100 senior recruits who play in the highest class. Olivia Nelson-Ododa of Winder-Barrow, the nation's top-rated junior according to espnW, suffered a knee injury in the region tournament and is done for the season.

Faithful to attend: Dodge County's girls have made the state tournament each season since 1992, the longest streak of its kind in history. Tift County (1994) has the longest boys streak. Laney's girls and the boys teams at Wilkinson County, Wheeler, Norcross and Westover have made it each season since 2000.

Conspicuously absent: Alexander's boys, ranked No. 6 entering the region tournament, failed to qualify. Southwest Atlanta Christian's girls, a Class A champion in 2006 and 2014 and semifinalist last year, is missing for the first time since 2003.

Newcomers: Four girls programs and four boys programs are in the state tournament for the first time. They are girls teams from Christian Heritage, Hapeville Charter, Locust Grove and New Manchester and boys teams from Cambridge, Islands, Lanier and Mountain View. Those programs are less than 10 years old.

Drought-breakers: Therrell of Atlanta hasn't put a boys or girls team in the state tournament since 1983, when the boys team made it. Now, both are in. That is likely the second-longest double drought ever to end behind Portal's 44-year streak (1957-2001), according to Becky Taylor of the Georgia Basketball Project. Meanwhile, North Springs' boys are in the tournament for the first time since 1982. Upson-Lee is the longest drought-breaker among girls (2000).

Never won: Another 40 teams that qualified have never won a tournament game. Those include Lakeside-Evans (No. 7 AAAAAA boys), Union Grove (No. 9 AAAAA boys), Heritage-Ringgold (No. 7 AAAA girls) and Hapeville Charter (No. 9 AA girls). Colquitt County's boys can advance for the first time in a home game against Kennesaw Mountain.

And finally: The finals three weeks hence will be played at Georgia Tech's McCamish Pavilion and Georgia's Stegeman Coliseum. Macon, the site of at least some of the finals every year since 1942, is out in part because of the embarrassment of last year's finals, which were played with rims positioned a foot closer to the baseline than is regulation. Georgia hasn't staged finals since 1941, nor Georgia Tech since 2003.