Try this:

\definepagebreak [chapter] [yes,header,right]

\setuphead [chapter] [page=chapter, ]

\setuppagenumbering[alternative=doublesided] \starttext \chapter {test} \dorecurse{10}{\input tufte } \chapter {test} \dorecurse{10}{\input tufte } \chapter {test} \dorecurse{10}{\input tufte } \stoptext

...

Sorry for this probably silly question, but I truely might be happy for an answer.

\definepagebreak is an undocumented feature. This definitely no silly question.

HTH,

Patrick

Hi Patrick, your example looks good. Unfortunately I use the project structure and have made each chapter a component: \startproduct Kueppers_Buch \project KPPRS_0 \startfrontmatter \completecontent \stopfrontmatter \component Einleitung \startbodymatter \component Kap_1 \component Kap_2 \stopbodymatter \stopproduct Now the left empty page after the TOC has a pagenumber and also the empty last left page of "Einleitung" befor "Kap_1" begins etc. Is \definepagebreak also extendable for this case?