The College Football Playoff semifinals are Thursday, Dec. 31.
The College Football Playoff committee ranked the elite in college football over a six-week period, and only Clemson and Alabama were left standing after the first edition of poll on Nov. 3.
How did they get there?
Well, Clemson -- armed with a Heisman finalist QB in Deshaun Watson -- notched three wins over top-10 teams in the CFP's final rankings with a nation-best 14 top-25 NCAA-tracked stats.
MORE: Top plays from the 2015 season
Stacked with talent from repeated recruiting conquests, Alabama overcame an early home loss to Ole Miss on the strength of a punishing defense (No. 2 in yards per play allowed) and Heisman winner running back Derrick Henry (1,986 yards/23 TD).
Three-seed Michigan State and four-seed Oklahoma both stacked their resumes with big wins.
The Spartans, while far from overpowering statistically, have four top-15 wins, which leads their Playoff peers.
The Sooners -- the only team nationally in the top-10 in offensive and defensive yards per play -- capped a torrid stretch with top-25 wins at Baylor (44-34) and Oklahoma State (58-23) and edged TCU at home (30-29).
Here's more on what made these teams elite in 2015.
1. Clemson
2015 Record: 13-0 (ACC Champion).
Good-to-great wins at the time (AP Top-25 -- 3): Notre Dame (6; 24-22), Florida State (16; 23-13), North Carolina (10; 45-37 at neutral site).
Good-to-great wins in retrospect (CFP Top-25 -- 3): Notre Dame (8), Florida State (9), North Carolina (10).
2015 Blue Chip Ratio: 13 (47 percent); 2015 class rating (247Sports Composite): 8.
Stats to watch (2015 ranks): Yards per play -- 21. Scoring D -- 18. Def. Yards per play -- 9. 3rd down D -- 2. Field position advantage -- 111.
2,800-yard passer: Deshaun Watson (3,512 yards/8.5 yards per attempt, 30 TD-11 INTs); 700-yard rushers/receivers: RB Wayne Gallman (1,332 RY/10 TD), WR Artavis Scott (805 RecY/5 TD). 40 catches or more: Scott (84), WR Charone Peake (40 catches/563 yards/5 TD); 80 carries or more: Gallman (243), Watson (163/887 yards/11 TD); 5 sacks or more: DE Shaq Lawson (9.5), DE Kevin Dodd (8), LB B.J. Goodson (5.5). 65 tackles or more: Goodson (126), LB Ben Boulware (120), S T.J. Green (98), Lawson (78), Dodd (73), S Jayron Kearse (68), DT Christian Wilkins (72). 8 TFL or more: Lawson (22.5), Goodson (14); 5 PBUs or more: CB Cordrea Tankersley (9), Kearse (8), Boulware (6), CB Mackensie Alexander (5). 70% FG rate: K Greg Huegel (88).
2. Alabama
2015 Record: 12-1 (SEC Champion).
Good-to-great wins at the time (AP Top-25 -- 5): Wisconsin (20; 35-17 at neutral site), at Georgia (8; 38-10), at Texas A&M (9; 41-23), LSU (2; 30-16), Florida (18; 29-15 at neutral site).
Good-to-great wins in retrospect (CFP Top-25 -- 3): Florida (19), LSU (20), Tennessee (23; 19-14).
2015 Blue Chip Ratio: 1 (77 percent); 2015 class rating (247Sports Composite): 1.
Stats to watch (2015 ranks): Yards per play -- 55. Scoring D -- 3. Def. Yards per play -- 2. 3rd down D -- 6. Field position advantage -- 16.
2,800-yard passer: N/A; 700-yard rushers/receivers: RB Derrick Henry (1,986 RY/23 TD), WR Calvin Ridley (893 RecY/5 TD). 40 catches or more: Ridley (75), WR ArDarius Steward (54 catches/600 yards/4 TD); 80 carries or more: Henry (339); 5 sacks or more: DE Jonathan Allen (10), LB Tim Williams (9.5), LB Ryan Anderson (5). 65 tackles or more: LB Reggie Ragland (90). 8 TFL or more: Allen (12.5), Williams (11.5), Anderson (9.5); 5 PBUs or more: LB Reuben Foster (8), DB Minkah Fitzpatrick (8), CB Cyrus Jones (7), Ragland (6). 70% FG rate: K Adam Griffith (72.4).
3. Michigan State
2015 Record: 12-1 (Big Ten Champion).
Good-to-great wins at the time (AP Top-25 -- 4): Oregon (7; 31-28), at Michigan (12; 27-23), at Ohio State (3; 17-14), Iowa (4; 16-13 at neutral site).
Good-to-great wins in retrospect (CFP Top-25 -- 4): Iowa (5), Ohio State (7), Michigan (14), Oregon (15).
2015 Blue Chip Ratio: NR (21 percent); 2015 class rating (247Sports Composite): 22.
Stats to watch (2015 ranks): Yards per play -- 72. Scoring D -- 19. Def. Yards per play -- 52. 3rd down D: 35. Field position advantage -- 21.
2,800-yard passer: Connor Cook (2,912 yards/24 TD-5 INT/7.9 YPA; 700-yard rushers/receivers: WR Aaron Burbridge (1,219 RecY/7 TD). 40 catches or more: Burbridge (80), WR R.J. Shelton (41/484 yards/4 TD); 80 carries or more: RB L.J. Scott (140/691 yards/11 TD), RB Gerald Holmes (108/534 yards/8 TD), RB Madre London (114/489 yards/3 TD); 5 sacks or more: DE Shilique Calhoun (10.5). 65 tackles or more: LB Riley Bullough (95), LB Darien Harris (82), S Montae Nicholson (76), LB Jon Reschke (74), S Demetrious Cox (72). 8 TFL or more: Calhoun (14.5), DT Malik McDowell (12); 5 PBUs or more: CB Arjen Colquhoun (10), Cox (7), DE Lawrence Thomas (5). 70% FG rate: N/A.
4. Oklahoma
2015 Record: 11-1 (Big 12 Champion).
Good-to-great wins at the time (AP Top-25 -- 5): at Tennessee (23; 31-24 2 OT), West Virginia (23; 44-24), at Baylor (6, 44-34), TCU (18; 30-29), at Oklahoma State (11; 58-23).
Good-to-great wins in retrospect (CFP Top-25 -- 4): TCU (11), Oklahoma State (16), Baylor (17), Tennessee (23).
2015 Blue Chip Ratio: 17 (37 percent); 2015 class rating (247Sports Composite): 15.
Stats to watch (2015 ranks): Yards per play -- 9. Scoring D -- 21. Def. Yards per play -- 9. 3rd down D -- 79. Field position advantage -- 27.
2,800-yard passer: Baker Mayfield (3,389/35 TD-5 INT/9.6 YPA); 700-yard rushers/receivers: RB Samaje Perine (1,291 RY/15 TD), RB Joe Mixon (749 RY/7 TD), WR Sterling Shepard (1,201 RecY/11 TD). 40 catches or more: Shepard (79), WR Dede Westbrook (42/674 yards/4 TD), WR Durron Neal (42/527 yards/3 TD); 80 carries or more: Perine (211), Mayfield (131), Mixon (110); 5 sacks or more: LB Eric Striker (7.5), DE Charles Tapper (7), DE Charles Walker (6). 65 tackles or more: LB Dominique Alexander (91), LB Jordan Evans (79). 8 TFL or more: Striker (16), Tapper (10); 5 PBUs or more: CB Zack Sanchez (7). 70% FG rate: Austin Seibert (77.3).
