From Fallen London Wiki

I will note this here, if your Prepared stat, which is to say the cumulative Watchful + Preparation is ≥ 285 425, this becomes better than <a href="/wiki/Eureka!" title="Eureka!"><img alt="" src="/w/images/thumb/a/ac/Lightbulb1.png/20px-Lightbulb1.png" decoding="async" width="20" height="26" srcset="/w/images/thumb/a/ac/Lightbulb1.png/30px-Lightbulb1.png 1.5x, /w/images/thumb/a/ac/Lightbulb1.png/40px-Lightbulb1.png 2x" /></a> <a href="/wiki/Eureka!" title="Eureka!">Eureka!</a> So is it worth it though? You might say, well, just keep the Unexpected Result, in such a case, we end up with a Watchful based challenge, for the exact results we get from <a href="/wiki/Eureka!" title="Eureka!">Eureka!</a>