Do you train to your strengths or your weaknesses?

Just curious which people think is more important, and how you structure your training. It is certainly easier to train to your strengths, and perhaps if you are strong enough at one thing your other sports matter less. Like if you are a really good cyclist, maybe you can create a big enough lead that running matters less. Or a fast runner that can catch those who beat them on the bike.

On the other hand, training to your weaknesses will likely give you the biggest benefit to your time. If your bike is good but your run is shit, being a better runner would likely benefit you more than than being great on the bike but still shit on the run.

Just trying to create some discussion, so what do you guys think?