This repeats the misconception that the 10x is the difference in productivity between average or median developer and the best developer. However the actual statistics is difference in productivity between the best and worst developer.
Judging from my personal experience and I would imagine that the median developer is a 3-4xer. With the wrost developers delivering a third as much, and other developers delivering 3 times as much.
The worst developers are a drain on any project. Delivering negative 'productivity' by producing code with a wide range of issues. Bugs, unmanageable code, non-performant code, memory issues... a maintenance nightmare.
10x's is not nearly enough.
The top programmers leverage many things. Existing libraries, past experience on failed/successful projects, OOP, design patterns, multiple programming languages (right tool for the job at hand), code generators if it makes sense. And best practices they have learned from others. And more.
Nathan Myhrvold former CTO at Microsoft had this to say about the differences:
‘The Top software developers are more productive than average software developers not by a factor of 10x or 100x or even 1000x but by 10,000x.’
Judging from my personal experience and I would imagine that the median developer is a 3-4xer. With the wrost developers delivering a third as much, and other developers delivering 3 times as much.