ground rules

[chasbo]

I've done high school (fresh & jv) where the third base dead ball territory is defined by the back stop fence extended. This is distinguished by a chalk line. On the first base side we have the back stop fence extended but about 10 feet behind this extended line is another fence that seperates the playing area with the parking lot. The home team usually uses this second fence as the dead ball line. My question is why when an overthrown ball touches this fence is it not a dead ball situation with an award. If the same thing happened on the third base side and an overthrow went past the chalk line, then it's a dead ball, but the coaches say that an overthrow on the first base side is still in play. If we used the back stop fence extended on the first base side as we do on the third base side then there would be a dead ball situation, correct?