This is one of those areas that are so hard to figure out. Many JV teams have players who play both JV and some Varsity. No doubt that the JV team is much better when they have one of the varsity pitchers come down and throw a no hitter then they are when they are pitching the typical JV starter. No offense but there is a reason why they are working things out on JV.
BTW, I have seen more JV scores posted this year then ever before. Again they are typically meaningless as those teams are only playing for expereince and nothing else. Weather they go 20-0 or 0-20 it is of no significance. It is the level of work that they get in as they improve thier skills and try to make the varisty team next season.