Above all, it's never blind chance: it's a chance that is always planned, but also always surprising. And I need it in order to carry on, in order to eradicate my mistakes, to destroy what I've worked out wrong, to introduce something different and disruptive. I'm often astonished to find how much better chance is than I am.

Gerhard Richter: text : writings, interviews and letters, 1961-2007 (ed. 2009)