im not sure if plariums trying to say sorry for 1 lego from 23 sacreds over the weekend but ill happily take the 5 sacred shards ive recieved in the last 2 days - id almost say its compensation lol 

It isn't "rubbish"; it just needs to be taken with a grain of salt.  Everybody knows that Raid players are magnificently suspicious and whiny and tend to experience the slightest in-game adversity as a personal insult.

That said, there's a conspiculously large amount of anecdotal evidence that something's up with the CB rewards.  The sheer volume of it suggests this isn't just statistical noise.  And I'll add my voice to the chorus.  My rewards have been dog**** for at least a few weeks now.   

The only way to tell would be to get a huge sample size.  Luckily, the community normally does handle things like that.  What Ash or what any commenter here gets in a month doesn't particularly matter in terms of a sample size.  I certainly wouldn't put it past them since they silently took away the blue shards from the lowest tier of CvC and very publicly removed the chicken and shard from the login rewards.

It's calculated server side but the rates are known client side, in fact they have been known for a long time. It seems that the rates were temporarily up to 33% for all types of shards in UNM and now they are back to a bit less than 15% (as they have always been)