An unpredictable first half of the college football season has plenty of teams celebrating unexpected Top 25 appearances.

No. 18 Memphis is in the poll for just the second time ever. No. 22 Temple is making its first appearance since 1979. No. 19 Toledo and No. 21 Houston give the Top 25 a couple more representatives from conferences that aren't part of the Power Five. No. 25 Pittsburgh was picked to finish sixth out of seven teams in the Atlantic Coast Conference Coastal Division before the season.

Here's a closer look at each of these five surprise entries in the Top 25.

No. 18 Memphis (6-0, 2-0 American Athletic Conference)

Memphis Tigers
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How they got here: The Tigers earned their 13th straight win Saturday with a 37-24 victory over No. 24 Mississippi, which was ranked 13th at the time. Memphis has come from behind in each of its last five games. The only other time Memphis reached the Top 25 was in 2004. It's a remarkable climb for a program that posted a combined record of 12-48 from 2009-13.

Names to know: Quarterback Paxton Lynch leads an offense that averages 46 points per game Lynch has completed over 70 percent of his throws with 13 touchdown passes and only one interception. Justin Fuente, a former TCU offensive coordinator, is one of the nation's top coaching prospects.

Remaining schedule: Friday at Tulsa, Oct. 31 vs. Tulane, Nov. 7 vs. Navy, Nov. 14 at No. 21 Houston, Nov. 21 at No. 22 Temple, Nov. 28 vs. SMU.

No. 19 Toledo (6-0, 3-0 Mid-American Conference)

Toledo football
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How they got here: Toledo's 6-0 start includes two wins over major-conference teams - a 16-12 victory over Arkansas when the Razorbacks were ranked 18th and a 30-23 triumph over Iowa State. Toledo's No. 19 ranking is its highest since 1997. Toledo hasn't allowed a sack all season and is giving up just 13.2 points per game.

Names to know: Terry Swanson has rushed for 472 yards while averaging 7.9 yards per carry. Kareem Hunt, who rushed for 1,631 yards last year, is back after missing three games due to a suspension and a hamstring injury. Alabama transfer Phillip Ely has thrown for 10 touchdowns and 1,379 yards. Orion Jones has nine tackles for loss and five sacks.

Remaining schedule: Saturday at Massachusetts, Nov. 3 vs. Northern Illinois, Nov. 10 at Central Michigan, Nov. 17 at Bowling Green, Nov. 27 vs. Western Michigan.

No. 21 Houston (6-0, 3-0 American)

Houston football
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How they got here: Houston's 6-0 start under former Ohio State offensive coordinator Tom Herman has given the Cougars their highest ranking since they were 18th in the final 2011 poll. The Cougars average 45.7 points per game and rank 10th nationally in rushing offense and 11th in rushing defense.

Names to know: Quarterback Greg Ward Jr. has 14 touchdown runs to match LSU's Leonard Fournette for first place among all Football Bowl Subdivision players. Ward is the only FBS player to average over 200 yards passing and 100 yards rushing per game. Steven Taylor has eight sacks and 13 tackles for loss. Demarcus Ayers has 46 catches for 562 yards.

Remaining schedule: Saturday at Central Florida, Oct. 31 vs. Vanderbilt, Nov. 7 vs. Cincinnati, Nov. 14 vs. Memphis, Nov. 21 at Connecticut, Nov. 27 vs. Navy.

No. 22 Temple (6-0, 3-0 American)

Temple football
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How they got here: Temple's 6-0 start has the Owls ranked for the first time since the end of the 1979 season, when they went 10-2 and won the Garden State Bowl to finish 17th. Temple's fast start includes wins over Penn State and Cincinnati. Temple has given up just 14.7 points per game.

Names to know: Jahad Thomas has rushed for 756 yards to lead the American, and he also has 10 touchdown runs. Tyler Malakevich has 52 tackles and three interceptions. He also recorded three of Temple's 10 sacks against Penn State.

Remaining schedule: Thursday at East Carolina, Oct. 31 vs. No. 11 Notre Dame, Nov. 6 at SMU, Nov. 14 at South Florida, Nov. 21 vs. No. 18 Memphis, Nov. 28 vs. Connecticut.

No. 25 Pittsburgh (5-1, 3-0 Atlantic Coast Conference)

Pittsburgh football
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How they got here: Pittsburgh is in the Top 25 for the first time since getting ranked 15th to start the 2010 season. Pat Narduzzi, Pittsburgh's fifth coach in five years, has helped the Panthers overcome a season-ending knee injury to 2014 ACC player of the year James Conner. Pittsburgh's only defeat was a 27-24 loss at No. 12 Iowa in a game decided by a 57-yard field goal as time expired.

Names to know: Tyler Boyd has 41 catches for 396 yards. No other Panther has more than 12 catches or 184 yards receiving. Qadree Ollison has rushed for 559 yards and averages 5.9 yards per carry.

Remaining schedule: Saturday at Syracuse, Oct. 29 vs. North Carolina, Nov. 7 vs. No. 11 Notre Dame, Nov. 14 at Duke, Nov. 21 vs. Louisville, Nov. 27 vs. Miami.

This article was written by Steve Megargee from The Associated Press and was legally licensed through the NewsCred publisher network.

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