# Why coordinate indicate middle of path constructed with controls rather then the start point

Consider this example

\documentclass[12pt]{article}
\usepackage{tikz}
\begin{document}

\begin{tikzpicture}
\draw (0,1)..controls +(2,4) and +(-2,-6)..(4,0)
..controls  +(2,6) and +(-2,-6.5)..(8,0)coordinate[pos=0](A);

\draw[<-](A)--+(0,2)node[above]{A};
\end{tikzpicture}

\end{document} Although I have mentioned pos=0 in coordinate[pos=0](A)! look like the path is divided into two paths ?

It's the defined behaviour. From section 17.8 Placing Nodes on a Line or Curve Explicitly: Previous coordinate in your case is (4,0) and current point is (8,0), therefore pos=0 is at (4,0).

Following example shows the same case with a path built with two segments:

\documentclass[12pt]{article}
\usepackage{tikz}
\begin{document}

\begin{tikzpicture}
\draw (0,0) -- (3,1) -- (4,5) coordinate[pos=0] (A) coordinate[pos=0.5] (B) coordinate[pos=.75] (C);

\path (A) node {A};
\path (B)node {B};
\path (C)node {C};
\end{tikzpicture}

\end{document} Technically these are two separate paths, but you can do

\documentclass[12pt]{article}
\usepackage{tikz}
\begin{document}

\begin{tikzpicture}
\draw (0,1)..controls +(2,4) and +(-2,-6)..(4,0) coordinate[pos=0](A)
..controls  +(2,6) and +(-2,-6.5)..(8,0);

\draw[<-](A)--+(0,2)node[above]{A};
\end{tikzpicture}

\end{document}