There are
n! ways to order
n-items. For six items then,
6! equals 720 unique combinations. Your
if code above enumerates 6, excluding the other 714 possibilities.
The following Tcl proc will "randomize" a list of elements for you:
proc randomize_list {original} {
set randomized [list]
set size [expr {[llength $original] + 1}]
while {[incr size -1]} {
set i [expr {int(rand() * $size)}]
lappend randomized [lindex $original $i]
set original [lreplace $original $i $i]
}
return $randomized
}