…with 4 straight cuts .

I was reading “Classic Brainteasers” by Martin Gardner (Orient Paperbacks edition ).

He gives the solution as 11 with illustrative figure.( The formula applicable is 0.5 xsquared +0.5 x +1, with x being number of cuts).

Now if the 4th cut is made horrizontally through the centre of pizza ,one can get 14 pieces ( double of 7 pieces ).

Only condition specified is 4 straight cuts, not size of pieces.

What am I missing ?