Why? Those other codices don't know how to react. We can all say there have been some ups and downs in codices in the fifth edition of 40k, with some codices floundering within a few months while others break down the door and take children's lunch money. As new codices have come out each has added some new consideration to how players view what is 'good' or 'viable' in the game, from a competitive view of playing 40k. While in free play homebrew erratas are accepted, when it comes to competitive play everyone plays with the same published rules, so if we're trying to bring codices back to competitiveness we need to focus on those rules and how they effect how the game is played. I'll discuss two different tournament formats and how one influences gameplay choices.
In my opinion, the 2008 space marine codex one of the most versatile codices that has been published in fifth edition. Each variant codex, in which I will include grey knights, each have something that they can do that the space marine codex can't do as easily or at all. This cuts both ways; there are some things that other codices cannot do as well as codex space marines can. I'll go into more of these later, but first let's look at one of the rising trends in 40k tournaments: multiple win conditions. This may or may not be part of the tournaments that you attend, if you attend tournaments, but these types of ideas tend to filter down from large tournaments.
These multiple win condition missions have two general types, which I will refer to based on the large tournament where they gained prominence: the NOVA Open and Bay Area Open (Nova and BAO, respectively) styles. The Nova format has been around for a few years and features one BRB mission type as the primary with others as secondary and tertiary, having victory points as a final tie breaker. The winner is determined by who wins the highest mission type (primary>secondary>tertiary), with the secondary mission only being referred to if there is a tie on the primary. In the Nova format a player whose army is poor at one mission can attempt to force his opponent to a tie on that mission and win by achieving another mission. If all of these missions are tied, then it simply comes down to who killed the most, as measured by points cost of units.
In the BAO style, all three BRB rulebook missions are in lay at the same time and the victor is determined by who wins the most (e.g. a player who has more kill points and points defeats one who holds both bases). This means that layers must try to win at two or all three of those mission types simultaneously, without the ability to attempt to deny their opponent the ability to exploit their weakness. I think this is a poorer format for the game because it makes fewer builds viable, in an environment where the oldest codices have few competitively viable builds available to them.
So, the question is how to do we beat the king? Well, outdoing paladins in kill point denial is extremely difficult and requires cowardice not worthy of the emperor's finest, so feth it. The game is table paladins or bust if you are fighting them and kill points are in play, so let's see if we can do it. The specifics of how I would plan to do it will be in the next Knight Fighting article, but I'm sure my compatriots will have a word or two of disagreement before then.