Probably, number of moves and density are playing role behind the idea to have some freebie and make it attractive, sell able product. There are free and semi-free databases on line, so they are simply adhering to the market.
why do i sometimes need to upgrade to see line?
Sort:
when using the computer analysis feature available on this site, sometimes it will tell me i need to upgrade to see the recommended computer line and other times it does not and will show me the line. why would the developers make this feature so inconsistent?