I dig the hell out of the stats site Breakdown Fights.com... I love that most of their features are interactive.
Here is some data of fight finishes by round put together by "Mike the Geek" :
Fight Finishes by Round
JANUARY 3, 2012
Sometimes it isnít enough to predict how a fight will finish (KO, submission, or decision). Sometimes we want to know in what round a fight will finish.
To answer that question we looked at all 3-round fights in the Fight Metric database that were won by either KO/TKO (left graph) or submission (right graph) and calculated the % that ended each round:
The graphs show that finishes most often come in the first round. Finishes in the 3rd round are very uncommon.
What about 5-round fights?
Similar story. About 2/3 of finishes come in either round 1 or 2. Finishes in the championship rounds are rare.
Conclusion: whether youíre betting props or just putting your fight picking skills to the test, picking a fight finish in late rounds is (statistically) a bad bet. If you think that the fight is going to finish by KO/TKO or submission, the smart money is on an early round victory.
Mike the Geek