pipe freezing and splitting question

[raaizin]

The main valve to the bottom drain in our pool has a slight leak. Over time the pressure of the water(8ft deep) causes it not to hold the pressure back. As a result water seeks its own level and works its way past the valve. We had the pool about 10 years and in that time only once the pipe cracked. I was thinking of leaving the valve open, would this give the ice enough room to escape without cracking the pipe. It is not to hard to replace but looking for a little less work. Any other thought would be helpful