About 4/10 failed, 5/10 did ok and then with 1/10 they would absolutely hit it out of the park - usually on something that looked about as promising as the other 10. They did this frequently enough that they clobbered the competition, who were mostly just trying to do normal product management stuff like user surveys, etc.
The most interesting thing was that most people if you'd have asked them before would have gone "I don't think you can turn this into an experiment" and then immediately adopted a different strategy. Somehow they always figured out a creative way of injecting a low cost experiment where most people would have imagined that it wasnt feasible to run any experiment at all. It required quite a lot of pressure/leadership from above.