Head-to-head · 14 bouts
Koboyama Daizo and Sadanoumi Koji have met 14 times in recorded sumo. Sadanoumi Koji leads 8–6.
Koboyama Daizo has won with: frontal push out (4), frontal force out (2).
Sadanoumi Koji has won with: frontal force out (5), slap down (1), frontal push out (1), head lock throw (1).
| Tournament | Day | Winner | Technique | Ranks |
|---|---|---|---|---|
| November 1981 | Day 8 | Sadanoumi Koji | Slap down | Maegashira 4 East vs Maegashira 12 West |
| July 1982 | Day 1 | Koboyama Daizo | Frontal push out | Maegashira 11 East vs Maegashira 11 West |
| May 1983 | Day 14 | Sadanoumi Koji | Frontal force out | Maegashira 3 East vs Maegashira 9 West |
| July 1985 | Day 9 | Koboyama Daizo | Frontal force out | Maegashira 11 West vs Maegashira 7 West |
| September 1985 | Day 11 | Sadanoumi Koji | Frontal force out | Maegashira 3 East vs Komusubi 1 West |
| November 1985 | Day 1 | Sadanoumi Koji | Frontal push out | Maegashira 7 East vs Maegashira 7 West |
| March 1986 | Day 3 | Sadanoumi Koji | Frontal force out | Maegashira 8 East vs Maegashira 6 West |
| May 1986 | Day 13 | Koboyama Daizo | Frontal push out | Maegashira 8 East vs Maegashira 11 East |
| September 1986 | Day 1 | Koboyama Daizo | Frontal push out | Maegashira 9 East vs Maegashira 9 West |
| January 1987 | Day 14 | Koboyama Daizo | Frontal force out | Maegashira 12 West vs Maegashira 9 West |
| July 1987 | Day 10 | Sadanoumi Koji | Head lock throw | Maegashira 11 East vs Maegashira 7 West |
| November 1987 | Day 5 | Sadanoumi Koji | Frontal force out | Maegashira 4 East vs Maegashira 11 East |
| January 1988 | Day 12 | Sadanoumi Koji | Frontal force out | Maegashira 9 East vs Maegashira 5 West |
| March 1988 | Day 15 | Koboyama Daizo | Frontal push out | Maegashira 2 East vs Maegashira 10 West |
Every bout between the two that is in this database (March 1958 onwards). Technique names follow NHK WORLD-JAPAN.