Originally Posted by QuiltnNan

is the finished size of the white block the correct size? i'm thinking it's a seam width issue.
on blocks like this, i oversize the outside red triangles. in this case, it's a little tricky because of the baseball blocks. you'd have to make the baseball block a smidge bigger, too. when sewing this unit to the white, you'd have to make the baseball point touch the center of the white side, as you have. then, when squaring up, make sure there is a 1/4 inch seam allowance where the two red triangles cross.. HTH