A thing I like about rugby is that the best teams have to hold two ideas in their head at once. On the one hand, they have to be ferocious bullies; on the other, they have to use grace and skill to put the ball where the space is. The mindset required to be good at one thing is the opposite of the one required to be good at the other. Very few teams are good at both.  Great equity investors have something of the same quality. They can draw on both sides of their brain at the same time. …