I would say the goal is not to have the highest probability of triggering a cascade, but rather, some combination of:<p>- high probability of triggering a cascade<p>- high probability of that cascade being "useful", that is, of being able to work outward from the cascade you opened. (Clicking on the empty corner and getting 1-3-1 on its borders means you still have to guess to escape the corner.)<p>- high probability of <i>not</i> leaving difficult areas for the end. (Coin flips are most likely to occur in corners and edges; in the middle of the board, you usually have information from multiple directions. It's still possible to be forced to guess in the middle, but it happens far less often.)<p>As a result, the strategy I've chosen on expert boards (based on experience, without particularly robust statistical backing) is to click the corners sequentially until I get one that allows me to open up more than a few squares. I occasionally lose a game on the second or third click this way, but I don't lose very many on late coin flips.