I think most blackjack players know that basic strategy gives you the best odds over the long run. There is no shortage of bad strategies out there, though. One of the most common mistakes that new players make is mimicking the dealer.
I understand why people would do that. They probably know that the dealer has a statistical advantage in blackjack – called the house edge. If not, they at least know that the dealer plays a lot more blackjack hands than they do, so if he knows what to do they should follow him! The problem is that they are wrong.
Dealers will always hit on a 16 or less and always stand on a 17 or more, unless they are at a table where the dealer hits a soft 17. The dealer also never splits or doubles down. If the player mimics that strategy, that results in a house edge of 5.48%. By comparison, basic strategy results in a house edge of 0.5%.
So why is mimicking the dealer bad strategy? It is not the hit or stand rules that the dealer follows that gives him an edge. It is other rules, such as the fact that the players play out their hand before the dealer draws a third card, giving you an opportunity to bust first.
If you mimic the dealer, you are giving up two of the biggest weapons in your arsenal: splitting and doubling down. Splitting pairs appropriately gives you the change to win two hands instead of one when you have good hands. Likewise, doubling appropriately gives you a chance to win double the money on a good hand. Giving up those pieces of basic strategy gives up the chance to make up for your losing hands. So stop trying to mimic the dealer when playing blackjack and be yourself, as long as “yourself” is someone who follows basic strategy!