A point $ P$ is chosen at random in the interior of equilateral triangle $ ABC$. What is the probability that $ \triangle ABP$ has a greater area than each of $ \triangle ACP$ and $ \triangle BCP$?

$ \textbf{(A)}\ \frac{1}{6} \qquad
\textbf{(B)}\ \frac{1}{4} \qquad
\textbf{(C)}\ \frac{1}{3} \qquad
\textbf{(D)}\ \frac{1}{2} \qquad
\textbf{(E)}\ \frac{2}{3}$
1. **Understanding the Problem:**
   We need to find the probability that the area of $\triangle ABP$ is greater than the areas of both $\triangle ACP$ and $\triangle BCP$ when point $P$ is chosen randomly inside an equilateral triangle $ABC$.

2. **Centroid and Medians:**
   The centroid $G$ of an equilateral triangle divides each median into a ratio of $2:1$. The centroid is also the point where the medians intersect, and it divides the triangle into three smaller triangles of equal area.

3. **Area Comparison:**
   For $\triangle ABP$ to have a greater area than both $\triangle ACP$ and $\triangle BCP$, point $P$ must be closer to side $BC$ than to sides $AB$ and $AC$. This means $P$ must lie in the region closer to $BC$ than to $AB$ or $AC$.

4. **Dividing the Triangle:**
   Consider the medians of $\triangle ABC$ which intersect at the centroid $G$. These medians divide the triangle into six smaller triangles of equal area. The condition that $\triangle ABP$ has a greater area than $\triangle ACP$ and $\triangle BCP$ implies that $P$ must lie in one of these six smaller triangles.

5. **Identifying the Region:**
   Specifically, $P$ must lie in the region closer to $BC$ than to $AB$ or $AC$. This region is one of the six smaller triangles formed by the medians, specifically the one that includes the centroid $G$ and is bounded by the medians from $A$ and $B$.

6. **Calculating the Probability:**
   Since the medians divide the triangle into six smaller triangles of equal area, and $P$ must lie in one of these six triangles to satisfy the condition, the probability is:
   \[
   \frac{1}{6}
   \]

The final answer is $\boxed{\frac{1}{6}}$