grid anchor

When your gridded widgets don't take up all the space in a window, the grid anchor command allows you to say how they are arranged within the overall space. Or quoting the man page:

grid anchor master ?anchor?

The anchor value controls how to place the grid within the master when no row/column has any weight. See THE GRID ALGORITHM for further details. The default anchor is nw.

Is there a way to change this so that the default revert to -anchor center instead of the 8.5 default of nw? Yes, there is: catch {grid anchor $path center} before all your grid calls (once for each master). Yes, this can take ages. No, there is no other way. See TK bug 2062394 for reference.