When investors are looking for a steady-eddy blue chip to consistently compound over the long run, many default to Berkshire Hathaway (BRK.A 0.16%). The industry's worst-kept investing secret may not be the best buy in this space though. That award could go to Markel (MKL 1.08%) a company many have dubbed a "baby Berkshire." Though it comes with slightly more risk, there is also the potential for a lot more upside.