My own thoughts on Markel versus Fairfax, of which i own both.
Both have the same essential building blocks for success -- honest management that puts the focus on increasing intrinsic value per share, a very long-term orientation, good insurance operations, and retention of earnings and thoughtful, long-term oriented capital allocation across a large menu of options. I own both because my thesis is these ingredients will produce good results over the long term.
Fairfax today trades more cheaply than Markel on a book per share basis, notwithstanding that it has much more float per share which gives Fairfax the potential for higher returns. Seems like the better buy today in my opinion.
That said, Fairfax has a lot higher risk tolerance than Markel. I feel quite confident that Markel will compound in high single digits over longer periods of time so long as Gaynor is at the helm. With Fairfax, i think they will do well, but i also think there is a chance they run into troubles, as they have in the past. Some of the uncertainty has been taken out because they are no longer acquiring big insurance companies and hedging, but they still have much higher risk tolerance than Gaynor, on both the equity side and the fixed income side. On equities, Fairfax is adventuresome (Greece, Africa, India, turnarounds, etc.), and they have home runs and they strike out sometimes too. Gaynor looks for long-term compounders based in developed counties, and dollar costs averages into positions. On fixed income, they take no credit risk and duration match. Fairfax has a huge fixed income portfolio and takes big swings with it. Much of it is based on top-down macro outlooks about macro interest rates and marco credit risk that they have (over the full course of time) a good record on, but that are extremely hard to get right consistently in my opinion. It introduces the potential for large outperformance or underperformance.
I like having both!