1) Buffett aims to beat the S&P500, not the mid cap S&P 400 or the nasdaq 100 or the nikkei or the ftse100. 2) The golden rule of investing IS to take outsized bets when warranted. Probably the only way to beat the averages.
Due to my short English, let me make sure what you write. Did you mean proportion of each bet is much more important depending on his market decision, isn't it? To outperform over the index.
i mean, as with life, now and then, when you have the conviction, you have to make a big bet. If you don't you will never get anywhere. Most of Buffet's wealth comes from doing this (e.g. 40% bet on washington post etc).
So you mean that maximum bet size of Buffet was 40% for the WP. My guess was such as 10% for one big investment, since his cash is BIG.
i think at the time WP was about to go bust but he threw 40% of his fund into it and it paid off big.