Changes

According to the most obvious definition, an '''Open File''' is a vertical column with no [[Pawn|pawns]] of either [[Color|color]] on it. [https://en.wikipedia.org/wiki/Aron_Nimzowitsch Aron Nimzowitch], however, stated in [https://en.wikipedia.org/wiki/Mein_System My System] that there is something like a partially open file. For example, if there is a white pawn on h2, then the H-File is open for white from square h3 onwards. This definition has never caught up with chess programmers, probably because it would encourage an artificial piece placement.