Stuart Macgill's New "Danger Ball"...
No, not really a new delivery but, for fear of getting it wrong, I've decided to title this video with the name the commentator has monkiered it.
My opinion, I think this is effectively the Shane Warne slider but bowled with the seam as the axis of spin (rather that the seam scrambled like warne's)
It's like an askew leg break; the angle at which the delivery is released means it has leg spin but is spinning backwards too.
As the ball lands on the seam, it grips on the pitch. The leg spin on the ball means it turns... but the askew, back-spinning action means it only turns fractionally.
I reckon bowled with a scramble seam, the ball would have gripped less a skidded on more, making the batsman a better candidate for LBW.
I am aware of textbook examples of similar, or the same, type of delivery (usually called the "backspinner" or "skidder").
Not a "danger ball" as such, but can be an effective delivery.
All,just my humble opinion.... I'm sure someone with superior knowledge will tell me differrent.