The 1951 NCAA football season finished with seven unbeaten major college teams, of which five were unbeaten and untied. Ultimately, the Tennessee Volunteers were voted the best team by the Associated Press, followed by the Michigan State Spartans, with the Vols having a plurality of first place votes (139 to 104). Tennessee lost in the Sugar Bowl to the equally undefeated and untied #3 Maryland Terrapins, but the postseason games were not taken into account by the major polls. Tennessee, Maryland, Michigan State, and Illinois all claim national championships for 1951.
During the 20th century, the NCAA had no playoff for the college football teams that would later be described as "Division I-A". The NCAA did recognize a national champion based upon the final results of "wire service" (AP and UPI) polls. The extent of that recognition came in the form of acknowledgment in the annual NCAA Football Guide of the "unofficial" national champions. The AP poll in 1951 consisted of the votes of as many as 307 sportswriters.^[3]
Though not all writers voted in every poll, each would give their opinion of the ten best teams. Under a point system of 10 points for first place, 9 for second, etc., the "overall" ranking was determined. Although the rankings were based on the collective opinion of the representative sportswriters, the teams that remained "unbeaten and untied" were generally ranked higher than those that had not. A defeat, even against a strong opponent, tended to cause a team to drop in the rankings, and a team with two or more defeats was unlikely to remain in the Top 20. Generally, the top teams played on New Year's Day in the four major postseason bowl games: the Rose Bowl (near Los Angeles at Pasadena), the Sugar Bowl (New Orleans), the Orange Bowl (Miami), and the Cotton Bowl (Dallas). Taken from https://en.wikipedia.org/wiki/1951_college_football_season

Final Stats:

			Overall			Conference			Polls
		Conf	W	L	T	W	L	T	AP Pre	AP High	AP Post
1	Maryland	Southern	10	0	0	5	0	0	16	3	3
2	Princeton	Ind	9	0	0	0	0	0	18	4	6
3	San Francisco	Ind	9	0	0	0	0	0		13	14
4	Michigan State	Ind	9	0	0	0	0	0	2	1	2
5	Georgia Tech	SEC	11	0	1	7	0	0		3	5
6	Illinois	Western	9	0	1	5	0	1	10	2	4
7	Tennessee	SEC	10	1	0	5	0	0	1	1	1
8	Virginia	Ind	8	1	0	0	0	0		13	13
9	Wisconsin	Western	7	1	1	5	1	1	15	7	8
10	Tulsa	MVC	9	2	0	4	0	0
11	Stanford	PCC	9	2	0	6	1	0		3	7
12	Holy Cross	Ind	8	2	0	0	0	0		15	19
13	Oklahoma	Big 7	8	2	0	6	0	0	4	4	10
14	Kansas	Big 7	8	2	0	4	2	0		20
15	California	PCC	8	2	0	5	2	0	5	1	12
16	Drake	MVC	7	2	0	3	1	0
17	Baylor	SWC	8	2	1	4	1	1	13	7	9
18	Notre Dame	Ind	7	2	1	0	0	0	14	5
19	Wyoming	Skyline	7	2	1	5	1	1
20	Miami (FL)	Ind	8	3	0	0	0	0		19
21	Colorado	Big 7	7	3	0	5	1	0
22	Washington State	PCC	7	3	0	4	3	0		16	18
23	Virginia Military Institute	Southern	7	3	0	5	0	0
24	Southern California	PCC	7	3	0	4	2	0		6
25	Clemson	Southern	7	3	0	3	1	0		16	19
26	Texas	SWC	7	3	0	3	3	0	11	4
27	William & Mary	Southern	7	3	0	5	1	0
28	Louisiana State	SEC	7	3	1	4	2	1
29	Kentucky	SEC	8	4	0	3	3	0	6	6	15
30	Cornell	Ind	6	3	0	0	0	0	20	12
31	Arizona State	BIAA	6	3	1	4	1	0
32	Mississippi	SEC	6	3	1	4	2	1
33	Brigham Young	Skyline	6	3	1	2	3	1
34	Texas Tech	BIAA	7	4	0	4	0	0
35	Utah	Skyline	7	4	0	4	1	0
36	Villanova	Ind	5	3	0	0	0	0		12
37	Columbia	Ind	5	3	0	0	0	0
38	UCLA	PCC	5	3	1	4	1	1		15	17
39	Boston University	Ind	6	4	0	0	0	0		16	16
40	Denver	Skyline	6	4	0	4	3	0
41	Washington & Lee	Southern	6	4	0	5	1	0
42	Texas A&M	SWC	5	3	2	1	3	2	6	4
43	Wake Forest	Southern	6	4	0	5	3	0
44	Temple	Ind	6	4	0	0	0	0
45	Fordham	Ind	5	4	0	0	0	0
46	Syracuse	Ind	5	4	0	0	0	0
47	South Carolina	Southern	5	4	0	5	3	0
48	Penn State	Ind	5	4	0	0	0	0
49	Purdue	Western	5	4	0	4	1	0
50	Pennsylvania	Ind	5	4	0	0	0	0	19	19
51	Northwestern	Western	5	4	0	2	4	0		13
52	Ohio State	Western	4	3	2	2	2	2	3	3
53	Colorado State	Skyline	5	4	1	3	3	1
54	Duke	Southern	5	4	1	4	2	0		16
55	Pacific	Ind	6	5	0	0	0	0		16
56	Houston	MVC	6	5	0	2	2	0
57	Arizona	BIAA	6	5	0	3	3	0
58	Texas Christian	SWC	6	5	0	5	1	0		11	11
59	Vanderbilt	SEC	6	5	0	3	5	0
60	Iowa State	Big 7	4	4	1	2	4	0
61	Rutgers	Ind	4	4	0	0	0	0
62	Hardin-Simmons	BIAA	6	6	0	4	1	0
63	West Virginia	Southern	5	5	0	2	3	0
64	Auburn	SEC	5	5	0	3	4	0
65	Arkansas	SWC	5	5	0	2	4	0		19
66	Georgia	SEC	5	5	0	2	4	0		13
67	Florida	SEC	5	5	0	2	4	0
68	Rice	SWC	5	5	0	3	3	0		18
69	Alabama	SEC	5	6	0	3	5	0	9	9
70	Bradley	MVC	4	5	0	0	3	0
71	Colgate	Ind	4	5	0	0	0	0
72	Michigan	Western	4	5	0	4	2	0	17	15
73	Dartmouth	Ind	4	5	0	0	0	0
74	Mississippi State	SEC	4	5	0	2	5	0
75	Marquette	Ind	4	6	1	0	0	0
76	Oregon State	PCC	4	6	0	3	5	0		15
77	Citadel	Southern	4	6	0	1	3	0
78	Tulane	SEC	4	6	0	1	5	0
79	Utah State	Skyline	3	5	1	2	4	1
80	Harvard	Ind	3	5	1	0	0	0
81	Santa Clara	Ind	3	5	1	0	0	0
82	New Mexico	Skyline	4	7	0	2	4	0
83	Detroit Mercy	MVC	4	7	0	2	4	0
84	Washington	PCC	3	6	1	1	5	1	8	8
85	Furman	Southern	3	6	1	1	4	1
86	Southern Methodist	SWC	3	6	1	1	4	1		15
87	Loyola Marymount	Ind	3	6	0	0	0	0
88	Iowa	Western	2	5	2	0	5	1
89	Boston College	Ind	3	6	0	0	0	0
90	Yale	Ind	2	5	2	0	0	0
91	Oklahoma State	MVC	3	7	0	3	2	0
92	Pittsburgh	Ind	3	7	0	0	0	0
93	Texas-El Paso	BIAA	3	7	0	2	4	0
94	North Carolina State	Southern	3	7	0	2	6	0
95	Minnesota	Western	2	6	1	1	4	1
96	Navy	Ind	2	6	1	0	0	0
97	George Washington	Southern	2	6	1	2	3	1
98	Richmond	Southern	3	8	0	2	6	0
99	San Jose State	Ind	2	7	1	0	0	0
100	West Texas A&M	BIAA	2	7	0	1	5	0
101	Brown	Ind	2	7	0	0	0	0
102	Indiana	Western	2	7	0	1	5	0
103	Army	Ind	2	7	0	0	0	0
104	Idaho	PCC	2	7	0	0	3	0
105	Montana	Skyline	2	7	0	1	4	0
106	Wichita State	MVC	2	7	0	2	4	0
107	Missouri	Big 7	2	8	0	1	5	0
108	Oregon	PCC	2	8	0	1	6	0
109	North Carolina	Southern	2	8	0	2	3	0
110	Virginia Tech	Southern	2	8	0	1	7	0
111	Kansas State	Big 7	1	7	1	1	4	1
112	Nebraska	Big 7	1	8	1	1	4	1	12	12
113	New York University	Ind	1	7	0	0	0	0
114	Northern Arizona	BIAA	1	7	0	0	1	0
115	Davidson	Southern	1	8	0	1	5	0
116	New Mexico State	BIAA	1	9	0	1	4	0
Most Points per game: 38
Maryland
Fewest Points allowed per game: 6
Wisconsin
Top NFL Players drafted in 1952
Rnd	Pick	Tm		Pos	CarAV ▾	College/Univ
7	80	CHI	Joe Fortunato	LB	66	Mississippi St.
3	34	DET	Yale Lary HOF	DB	65	Texas A&M
1	4	GNB	Babe Parilli	QB	60	Kentucky
2	14	DTX	Gino Marchetti HOF	DE	56	San Francisco
1	1	RAM	Billy Wade	QB	48	Vanderbilt
11	133	RAM	Sam Baker	K	45	Oregon St.
6	68	CHI	Ed Brown	QB	37	San Francisco