75.6% win rate for accused patent infringers.  Patentees lose 75.6% of the time against accused patent infringers.  “An empirical study of the results of patent litigation at the appellate level during the period 2002-2004. Dispositive case results, i.e., those not involving a remand on the merits, are compiled. Patent owners won 24.43% of the cases and accused infringers the remainder. The cases were further analyzed to determine the characteristics of winning and losing parties, including nationality, financial strength, location of principal offices, and several other factors.”  Patent infringer.  What is the success rate of challenges to a patent?   (Paul M. Janicke, University of Houston Law Center and Lilan Ren, University of Houston, “Who Wins Patent Infringement Cases?,” American Intellectual Property Law Association Quarterly Journal, Vol. 34, p. 1, 2006)

40% of decisions rendered by The Court of Appeals favorable to plaintiffs in patent infringement suits.  “The Court of Appeals for the Federal Circuit, which handles all the patent cases that are appealed from District Court opinions, has been favoring plaintiffs in infringement suits only 40 percent of the time, compared with 60 percent earlier.”  (Claude Barfield and John E. Calfee, “Patents pending: the U.S. patent system is more important than ever. It's also a mess,” The American, Washington, DC, January 1, 2008)

25% win rate for patent owners.  Patent owner long-term contested win rate.  “The long-term contested win rate for patent owners varies around 25 percent.” Patent win rates.  Patent lawsuit chances  (LegalMetric press release, “LegalMetric Data Of KSR Effect On Patent Owner Win Rates,” eWorldwire, September 12, 2007)