Let E be a Banach space and let $ℬ₁\left(B_{E*}\right)$ and $₁\left(B_{E*}\right)$ denote the space of all Baire-one and affine Baire-one functions on the dual unit ball $B_{E*}$, respectively. We show that there exists a separable L₁-predual E such that there is no quantitative relation between $dist(f,ℬ₁\left(B_{E*}\right))$ and $dist(f,₁\left(B_{E*}\right))$, where f is an affine function on $B_{E*}$. If the Banach space E satisfies some additional assumption, we prove the existence of some such dependence.