Agreed, for new players who don't have such a huge edge over the field down there 20 might not be enough though. The 20x would be for a player beating the game for a decent winrate. At higher stakes, even the best players have a much lower winrate, thus variance is higher and more buyins are needed, it also depends on how aggressive the games are. I mean there are days were I win all the AKvsQQ/JJ all ins, and days were I loose them all.