I just cut a fresh sheet of MDF.
I need 4 15" wide cuts, and 2 18" wide cuts. I plotted it out on Sheet Cutting Suite, and it looked as if I wouldnt be able to get the last 18" cut out of it. All of these cuts were horizontal in portrait veiw of the sheet, if you understnad what I mean.
I cut the 4 15's, and then one of the 18". To my eye it looked as if the last peice would be too narrow, so I put it against the guide, and it snuggly fit against the blade. I then called myself a pimp, and tested it against the other 18" wide board...
It was a perfect fit.
My day has been perfect.