Corwin's Silver Pattern is one of the two Primal Patterns. It has two major reflections, or possibly one: in Maetri and Clarenne, two cities on opposite sides of a thin flat world. It controls a sweep of Shadow out to Amber, Rebma, and Tir na Nog'th in one direction and out to the Abyss in another, but the division between Shadows is not infinitely fine: there are some Shadows that only one Pattern can reach. Further, it is hard to find worlds containing great quantities of dynamic change using Corwin's Pattern: the tendency is towards peaceful, stable realms.
Dworkin's Blue Pattern is the other Primal Pattern. It has three major reflections, in Amber, Rebma, and Tir na Nog'th. It controls a sweep of Shadow out to Maetri and Clarenne in one direction and out to the Abyss in another, but it also does not have an infinitely fine division of Shadow: it is hard to find Shadows with a time flow greater than 5:1, or technology much advanced over Shadow Earth. Again, there are some Shadows reachable by Corwin's Pattern that are not reachable via Dworkin's Pattern.
Both Patterns seem to require the same bloodline to walk them: that is, while someone not of Oberon's blood will burn to death on either Pattern, it does not seem to further require descent from Corwin to walk _his_ Pattern. There are broken reflections of each of these Patterns, although all the broken versions of Dworkin's Pattern are _very_ broken, that can be walked by any Shadow of strong enough will.
Note: in order to find a place where one of the three Powers of the multiverse does not work (one of Logrus, Corwin's Pattern, or Dworkin's Pattern), one must have a good familiarity with that power, such as comes from being initiated into it, or spending a great deal of time in the Shadows where its reflections are. Then one must have another Power with which to actually get there and back.
Shavings of True Stone