NCAA basketball seed records

For some reason this weekend I got to thinking about which seed numbers have faced each other in the NCAA men's basketball tournament. We know that no 16 seed has ever beaten a 1 seed so other than the 16v16 play-in games - no other seed has faced a 16. But which other match-ups have never occurred?

The tournament committee started seeding teams in 1979 and the tournament went to 64 (and beyond) starting in 1985.

I found this "betting guide" article that referenced the first two rounds prior to this years tournament. I combined this with a quick (probably multiple errors) scan of wikipedia to pull together a table of which seed numbers have faced off and what their record is.

Here's what I came up with in tabular form - read across for wins and down for losses. This also includes the old third place games played with seeds from 1979-1981.

Seed	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	total
1	22	37	20	36	40	10	5	67	67	5	3	18	4	0	0	128	462
2	3	2	34	4	1	26	66	4	2	33	13	1	0	0	120	0	309
3	13	23	1	5	2	46	9	2	2	9	35	0	0	107	1	0	255
4	22	5	3	1	50	2	2	3	2	2	0	26	102	0	0	0	220
5	8	6	2	40	1	1	0	3	1	1	0	100	12	0	0	0	175
6	5	8	39	4	1	0	4	0	0	6	96	0	0	14	0	0	177
7	1	26	5	4	0	3	0	1	0	92	0	0	0	1	2	0	135
8	17	4	0	5	2	3	1	0	80	0	1	0	1	0	0	0	114
9	7	1	0	1	2	0	0	72	0	1	0	0	1	0	0	0	85
10	0	22	4	0	0	4	60	0	0	0	0	0	0	1	5	0	96
11	3	1	14	0	0	52	3	0	0	1	1	0	0	5	0	0	80
12	0	0	0	12	49	0	0	1	0	0	0	0	8	0	0	0	70
13	0	0	0	25	3	0	0	0	0	0	0	3	0	0	0	0	31
14	0	0	21	0	0	2	0	0	0	0	0	0	0	0	0	0	23
15	0	8	0	0	0	0	1	0	0	0	0	0	0	0	0	0	9
16	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Total	101	143	143	137	151	149	151	153	154	150	149	148	128	128	128	128

So the missing match-ups are:

• 1 vs 14, 15
• 2 vs 13, 14, 16
• 3 vs 12, 13, 16
• 4 vs 11, 14, 15, 16
• 5 vs 7, 11, 14, 15, 16
• 6 vs 6, 9, 12, 13, 15, 16
• 7 vs 5, 7, 9, 11, 12, 13, 15, 16
• 8 vs 8, 10, 14, 15, 16
• 9 vs 6, 7, 9, 11, 12, 14, 15, 16
• 10 vs 8, 10, 11, 12, 13, 16
• 11 vs 4, 5, 12, 13, 15, 16
• 12 vs 6, 7, 9, 10, 11, 12, 14, 15, 16
• 13 vs 2, 3, 6, 7, 9, 10, 11, 13, 14, 15, 16
• 14 vs 1, 2, 4, 5, 7, 8, 12, 13, 14, 15, 16
• 15 vs 1, 4, 5, 7, 8, 11, 12, 13, 14, 15, 16 

Are there any of the missing combos that could still happen this year?

If Gonzaga and Iowa St. win in the Midwest it would yield the first 4 vs. 11 match-up. A Gonzaga trip to the final four facing Indiana or Finals against Maryland would be the first 5 vs. 11 match-ups as well. But beyond that we've seen all these seeds face off before.

Michigan has been involved in at least 2 of the "only happened once combinations. The 1989 final vs. Seton Hall was the only contest between 3 seeds. The 2013 semifinal vs. Syracuse is the only time 2 #4 seeds have faced off.