#0 - Feb. 11, 2010, 12:22 p.m.
Ghostcrawler argued that though DKs are not good on most comps they seem to do fine on certain teams (presumably referring to TSG and PHD). The success of particular comps (rather than just the class) may be relevant some of the time, but it can be misleading, particularly if people don't consider the reasons for a comp's high representation. There are several reasons a comp can be well represented among the more successful teams.
1) The classes on it are powerful.
2) The classes on it have a lot of synergy.
3) The comp was very good in the past and the players did not want to switch comps.
4) It is a lot better than the other options for one class so that class gets pigeonholed into that comp.
Successful comps usually have a combination of these factors going for them, but how the success of these comps should influence balancing changes should depend on precisely which of these factors are in place.
The DK comps that are "successful" right now are TSG and PHD. TSG was great in S5 (and to a lesser extent S6) due to reasons 1 and 2. PHD is a newer comp (mainly because hunters are better than they were in late S5/S6). These two teams are played a lot now because of reasons 3 (TSG) and 4 (both TSG and PHD). Thus, these comps' success does not necessarily contradict the claims that DKs are a very weak PVP class right now.
The problem is that DKs fulfill a niche that is inferior to what other classes bring to the table. They're good at control (CoI, DG), anti-casting (Mind Freeze, Strangulate), and defenses (plate, AMS, AMZ). They also do a decent amount of sustained damage, but that's not very valuable in arenas because it's too easy to heal through. Burst damage, healing debuffs, or CC are what kills in 3v3 and DKs bring none of these. In short, (unlike S5) DKs are now a support class.
This isn't a good state because a support class needs their teammates more than the teammates need them. The DK's teammates can get another class (including one that actually does killing itself) and do just as well, if not better. If the DK tries to find another team he/she will be anywhere from terrible (if the partners can't fulfill those roles) to decent (if they can fulfill them).
Ultimately, I think this problem is bigger than an adjustment to Scourge Strike or disease protection can solve. DKs need to be altered to fulfill a niche that is more valuable to the team than just support (at least one or two of the following: healing debuff, burst damage, CC). When this occurs (or if it does at all) won't affect me much. My teammates and I have moved on and are not using our DKs for now. I do feel that DKs deserve more attention, though, and it would be a shame if it had to wait until Cataclysm.