tag:blogger.com,1999:blog-38600807.post8281353153517607645..comments2009-07-17T01:58:02.771-04:00Brian Burkenoreply@blogger.comBlogger4125tag:blogger.com,1999:blog-38600807.post-89888986524343936292009-07-17T01:58:02.771-04:002009-07-17T01:58:02.771-04:00I&#39;m working on a project that needs to incorporate fumbles as a measure of rush defense and I&#39;ve arrived at conclusions similar to yours. The best measure would be fumbles truly forced by the defense, regardless of who recovers. But like I said, I&#39;m looking at this as a measure of rush defense, so I want to exclude fumbles produced on sacks, as they&#39;re clearly a component of pass defense. Do you have a source for fumble stats that could provide detail at this level?Justinhttp://enamelmedia.comnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-3553658544337471362008-03-04T13:59:00.000-05:002008-03-04T13:59:00.000-05:00I just looked at some numbers. Actually, it appears that prior fumble rates predict future fumble rates (within the same season) at a 0.33 correlation. Sack rates predict fumble rates at only 0.15, which is pretty small and barely significant. I'm sure it would be higher for forced fumbles, but I don't have mid-season forced fumble data to check. <BR/><BR/>Regardless, I think you're point is correct.Brian Burkehttp://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-38545947599102348632008-03-04T13:15:00.000-05:002008-03-04T13:15:00.000-05:00jworkm-<BR/>Excellent point. At first I didn't understand what you were saying, but now it's clear. It would probably be best to account for the fact a sack did not occur on an incomplete pass.<BR/><BR/>What I was originally trying to do was evaluate a defense's ability to force a fumble during a tackle. Since there is never tackle on an incomplete pass, there would be no possibility of forcing a fumble. <BR/><BR/>But you're right, a defense that gets a lot of sacks also probably forces a lot of fumbles by the QB. In the context of assessing a team's ability to generate fumbles, sack rates would be critical. <BR/><BR/>In fact, I'd bet sack rates are one of the best predictors of future forced fumbles--even better than previous forced fumbles to date. <BR/><BR/>Thanks.Brian Burkehttp://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-76273256571607287462008-03-04T12:37:00.000-05:002008-03-04T12:37:00.000-05:00Can you explain to me why you have omitted incomplete passes from consideration with regard to forced fumbles.....it seems to met that there still exists the opportunity for the defense to force a fumble in the way of a sack. How are we to know whether the pass that would have been thrown by a qb who is sacked and fumbles would have been complete or incomplete???jworkm05http://www.blogger.com/profile/17979068720962030870noreply@blogger.com