I don't know if I'm doing these posts correctly so forgive me if this is a dup, but what is a cracked planchette? Please and thank you!
A cracked planchet and the effect the OP is looking at are two different things.
What OP is looking at is split plating, this occurs when the copper plating is split away during the strike, exposing the zinc core of the cent. This is an effect unique to zinc Lincoln cents as far as I am aware, and fairly common. You can see this usually on the outer edges of the peripheral letters on the cent, as is evident on this cent.
A cracked planchet is an error that is fairly self described, before a coin is struck, the planchet itself got damaged that caused it to crack, and was struck with the crack, these are extremely uncommon errors. here is a reference: http://www.error-ref.com/cracked-planchet/