<i>My most successful (commercial) project was done without tests, and it is a huge success</i><p>Kinda like saying: Seatbelts have no value by themselves; my parents drove their whole lives without them and didn't die.<p>The issue is not whether every project that doesn't use tests will fail (it certainly won't). The question is whether over all projects, and on balance, do tests have value. Yes, they do.