Estimates for tasks/apps/games/projects that have been done before, or known from previous work are usually pretty close. Like for instance making another versi

Estimates for tasks/apps/games/projects that have been done before, or known from previous work are usually pretty close. Like for instance making another version of a puzzle game with changed assets and maybe a few new features. Estimates for tasks/apps/games/projects that have NOT been done before, or known from previous work are usually wildly incorrect. Like for instance making the first version of a puzzle game with new everything. Even more so for a new game type that you haven't done before. Software estimation is like 65% correct (2/3rd) usually. There are so many internal, external and just unknown areas that usually these are underestimated greatly. The estimation is off by more when there are third parties or components/frameworks that get you 90% of the way but make the last 10% more tasking than custom sometimes. The nature of software design and development is usually creating new value, in that case lots of those projects are unknown or the first time through something, estimation is almost useless in those areas. It is better to do prototypes to help refine and break it up into parts that can better be estimated. Anyone doing an estimate on a new area that hasn't had a prototype will always be wrong. Estimates more than a month out are also wildly wrong. When you are asked to estimate something big, always just do an estimate for a prototype first before you ever begin to try to estimate the rest.