There are 12 SHADES in the Colour Basics deck.
Six are Shades of the Corner Colours, and six are Shades of the Connector Colours. Because they contain equal parts of both the base Hue and Black, they can be grouped with the Shades, or with their colour family.
There are 60 SHADES in the BTC deck.
Shades that contain more Black than Hue are grouped with Black. Shades that contain more Hue than Black, while still classified as Shades, are grouped with their colour family.
There are no 'half Black, half Hue' Shades in the BTC deck.