I know this is a rather old topic, but I was looking up discussions surrounding the same question. I might as well give my 2 cents to hopefully get the discussion rolling. Enough rambling on why I am posting on an old post. Onto furthering the greater good!Introduction to the White Scars
White scar bike armies are one of the top armies out there, in fact it won the bay area open in 2014.
A general list will look like this: http://bloodofkittens.com/wp-content/up ... rines-.pdf
The army pretty much consists of a command squad on bikes, 4-5 bike squads. Each bike squad consists of 3 bikes, 1 sergeant and 1 attack bike. Armament
Each squad will pack a multi-melta (attack bike), 2 grav/melta/plasma (bikes) and a combi weapon with the sergeant. Their close combat capabilities is actually not that great, with only 6 attacks per squad when charged. However they do get s5 HoW attacks on the charge.Movement
The most deadly thing about the white scars is that it can cover distances faster than any army out there. This as you can imagine, poses a huge threat to our great tau empire. Bikes can deploy right at the edge of their deployment zone and scout move 12 inches up due to their chapter master. So even before the first turn (which I sure hope you are going first) the bikes can be only 12 inches from your deployment zone.
Also remember that white scars ignore all dangerous terrain tests and have 3++ jink save!Possible Counters
I have to state that I am definitely NOT a great 40k player, maybe not even above average.... but I was hoping that this thread can fuel more discussion so I can gleam some knowledge from it too. Objective Placement
Bikes take up a lot of space, and the white scars commander would want to deploy them as far forward as possible. The result would be one straight line of bikes across his board at the forward edge of his deployment zone.
Hence you would want to place objectives heavily on one side of the field so that it makes the other side practically irrelevant. All the bikers that gets deployed on the empty side will have to come all the way to your board edge and swing around, which would take them an extra turn to start shooting you.Reserves
That goes without saying you want to reserve troops vulnerable to alpha strike (no *BAD WORD DELETED!* Einstein)Infiltration
I think this is the most important part to counter the enemy's 12" scout. The cheapest unit to do so would be kroot. Infiltrate step occurs before scout moves. If you are able to infiltrate your kroot 12" from the enemy front line, then they cant make any scout moves within that 12" bubble around your kroot. You would want the kroot to infiltrate on the side loaded with objective markers.Close Combat
Believe it or not close combat is probably one of the weakest aspect of the bike army. Each squad only has 6 standard attacks when charged. I guess that is why all bikes have the hit and run ability. You can charge in with a squad of kroot and kroot hounds. The bikes will probably hit and run away at the end of combat, but they will have to run backwards! Vehicle Road Blocks
If you have a piranah or devilfish that has off loaded its troops, they can be used to block the enemy advance. Run your expendable vehicles right into their faces so the bikes wont be able to move without destroying the vehicles. This is intended for useless vehicles, don't run your hammerheads or what nots in their. The melta fire will eat that vehicle up.
I hope their will be a bit more discussion after this to help our might empire to victory against these marine bikers clad in cheese white armour.