ESPN is a sports channel that covers a lot of common sports that are popular in the United State and Canada. Since ESPN founders were associated with hockey because their previous job was with hockey, that sport is definitely included on ESPN. However, there are some sports that ESPN does not cover. This may be because there are sports that are not popular and only have a very limited audience in general.
So, not many people would watch this sport on television because people are not interested in it. Some of these sports include MMA and boxing. It is not known why these sports are not on ESPN since they are and have become more and more popular. Some of the other sports not on ESPN might include shooting and fencing.