You can run Chrome with a command line flag
--auto-open-devtools-for-tabs which will automatically open up DevTools in each new tab. This can be useful for some automation use cases, but also if you find yourself repeatedly opening up DevTools during your debugging sessions.
The full command you can try out (OS X) is:
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --auto-open-devtools-for-tabs